2013 Practice-Ready Papers

• Kansas City Crosstown Improvement Project Evaluation: Results and Lessons Learned
  Abstract: This report summarizes the findings of an independent evaluation of the FHWA Cross-town Improvement Project (C-TIP), which was deployed in Kansas City and Chicago in various periods from October 2010 through September 2011. The Dynamic Route Guidance (DRG) and Real-Time Traffic Monitoring (RTTM) components of C-TIP achieved measurable dray truck travel time savings and emissions reductions in operational tests. Separate deployments of in-cab smart phones running the C-TIP Open Source Architecture Package with drayage companies in Kansas City and Chicago achieved measurable reductions in bobtails even as revenue loads grew or remained stable. Simulations of the Intermodal Move Exchange (IMEX) component of C-TIP revealed the potential to reduce bobtails through better information sharing between cross-town railroads and drayage firms. There were some operational constraints to full utilization of C-TIP in Kansas City. Changing railroad business practices, along with a generally low level of economic activity during the test, contributed to limited railroad participation in the program. More broadly, the test experience suggests that the intermodal industry culture may not provide the collaborative culture necessary to make a cooperative dispatch platform work. Nonetheless, this initial deployment of C-TIP technologies did prove the concept that such applications can provide public and private sector benefits including congestion mitigation, emissions reductions, and truck travel time savings. The results suggest that future research may be best targeted towards freight information exchange, improving the truck dispatch operation, and in providing real-time information and tools to support truck routing decisions.
  Authors: Schiller, Roger T.; Butler, Randy; Jensen, Mark
  Authors: Schiller, Roger T.; Butler, Randy; Jensen, Mark
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 407
  Paper Number: 13-0097
  Practice-Ready: Yes
• Condition Evaluation of the Nation’s Bridge Infrastructure Using Indicators Extracted from National Bridge Inventory Source Files
  Abstract: As bridges continue to age and deteriorate, the Nation is facing significant repair, maintenance andreplacement costs, as well as an increase in safety hazards to the motoring public and a decrease inefficiency to the trucking industry. Bridge conditions are of immediate concern to public safety, economyand national security. Compounding the issue is a chronic lack of adequate resources to performrecommended maintenance and repair, a continual increase in the weight and numbers of heavycommercial vehicles, and a dramatic reduction in the number of new bridges built or replaced annuallyover the last decade. Essential to addressing this issue is a simple to use, easily accessible means to assesscurrent conditions and to identify specific historical trends that may contribute to these conditions. For thepast two decades the primary source of publicly available information on the condition of the nation’sbridge infrastructure has been the National Bridge Inventory (NBI) data files compiled and provided bythe Federal Highway Administration. In 2009 the New Mexico Department of Transportation created asoftware application, the SABIS Bridge Information System, that processes publicly available NBI sourcefiles and provides simplified access to this information for use by technical and non-technical end users.This paper presents the results of efforts by the Research Bureau of the New Mexico Department ofTransportation to examine ten specific indicators of the condition of the nation’s bridge inventory usingdata extracted from these source files. These indicators are described in Federal Report No. MH-2009-13,“National Bridge Inspection Program: Assessment of FHWA’s Implementation of Data-Driven, Risk-Based Oversight”, and pertain primarily to the load rating and posting status of the nation’s bridges.
  Authors: Daniell, Keli T
  Authors: Daniell, Keli T
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 620
  Paper Number: 13-0061
  Practice-Ready: Yes
• Axle and Length Based Vehicle Classification Performance
  Abstract: This study evaluates the performance of three freeway, permanent vehicle classification stations against concurrent video based ground truth. All of the stations have dual loop detectors and a piezoelectric sensor in each lane, providing both axle-based and length-based classification. The evaluation is done at the individual, per-vehicle resolution for each vehicle that passed during the study periods (over 18,000 vehicles, uncongested). While the stations exhibited good performance overall (97% correct), the performance for trucks was far worse, e.g., only 60% of the single unit trucks (SUT) were correctly classified. We diagnosed all of the observed errors and some can be fixed quickly while others cannot. Using data from one site, we revise the classifier to solve almost all of the fixable errors and then test the performance at another location.One chronic error found in this research is intrinsic to the vehicle fleet and may be impossible to correct with the existing sensors; namely, the shorter, SUT have a length range and axle-spacing range that overlaps with passenger vehicles (PV). Depending on the calibration, the error may be manifest as SUT counted as PV or vice versa. One should expect such errors at most classification stations. All subsequent uses of the classification data must accommodate this unavoidable blurring error. The blurring also means that one cannot blindly use an axle classification station to calibrate the boundary between PV and SUT for length-based classification stations, otherwise, the unavoidable errors in the axle-based classification will be amplified in the length-based classification scheme.
  Authors: Kim, Seoungbum; Coifman, Benjamin
  Authors: Kim, Seoungbum; Coifman, Benjamin
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 353
  Paper Number: 13-0058
  Practice-Ready: Yes
• In-service Performance Evaluation of Cable Median Barriers on Florida’s Limited-Access Facilities
  Abstract: This paper presents a study to evaluate the safety performance of cable median barriers on limited access facilities in Florida. The safety evaluation was based on the percentages of barrier and median crossovers by vehicle type, crash severity, and cable median barrier type (CASS and Gibraltar systems). Twenty-three locations with cable median barriers totaling about 101 miles were identified. Police reports of 8,818 crashes from years 2003-2010 at these locations were reviewed to verify and obtain detailed crash information. A total of 549 crashes were determined to be cable median barrier related (i.e., crashes involving vehicles hitting the cable median barrier) and were reviewed in further detail to identify crossover crashes and the manner in which the vehicles crossed the barriers, i.e., either by over-riding, under-riding, or penetrating the barriers. A relatively low 2.6% of vehicles that hit the cable median barrier crossed the median and traversed into the opposite travel lane. Overall, 98.1% of cars and 95.5% of light trucks that hit the barrier were prevented from crossing the median. Further, 16.4% of barrier related crashes crossed over the barrier but did not cross the median. Overrides were found to be more severe compared to under-rides and penetrations. The statistics showed that the Gibraltar system experienced a higher proportion of penetrations compared to the CASS system. The CASS system resulted in a slightly higher percentage of moderate and minor injury crashes compared to the Gibraltar system.
  Authors: Alluri, Priyanka; Haleem, Kirolos M.; Gan, Albert
  Authors: Alluri, Priyanka; Haleem, Kirolos M.; Gan, Albert
  Year: 2013
  Document Type: Paper
  Subject: Design
  Session: 730
  Paper Number: 13-0149
  Practice-Ready: Yes
• Vulnerability Assessment of Bridges Exposed to Scour
  Abstract: In order to improve funding allocation for transportation infrastructure maintenance and risk mitigation, there is dire need for a simplified yet sufficiently accurate methodology for estimating bridge vulnerability to scour. The methodology should make use of existing data and indicate basic variables needed for vulnerability assessment of bridges in road network located in the southeastern Serbia around the future expressway. In the first part of the paper the identification of possible bridge failure modes due to scouring event which depend on soil, structure and river hydraulic properties is discussed. Here, degradation of soil parameters is assumed as the main cause of bridge failure. The capacity of a bridge to withstand certain amount of structural damage governs both direct and indirect costs as the bridge failure and subsequent work zones related to rehabilitation actions reduce performance of the whole network. In the second part of the paper, the simulation of redistribution of traffic flows has been performed for several different possible scenarios using software VISUM. These scenarios include partial and full closure of road links due to bridge failures. The simulations confirmed that the most significant contribution to indirect costs stems from increase of total travel time for all network users.
  Authors: Tanasic, Nikola Slobodan; Ilic, Vladan Nedjo; Hajdin, Rade
  Authors: Tanasic, Nikola Slobodan; Ilic, Vladan Nedjo; Hajdin, Rade
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 462
  Paper Number: 13-0191
  Practice-Ready: Yes
• Measure for Measure: Using Energy Utility Model to Standardize Evaluation of Transportation Efficiency Measures
  Abstract: As the environmental and financial costs of conventional gasoline become more apparent, there is growing interest in the concept of transportation efficiency. Broadly, this concept involves using less energy to meet current travel demand and often employs a systems-level approach. The transportation sector has much to learn from the electric and thermal energy sectors, where demand management strategies have used established screening tools to assess the environmental and financial benefits of efficiency measures for years. Adoption of such screening tools may be ideal for the transportation sector as electric vehicles (EVs) bring these two sectors together. We present an example of how the Vermont State efficiency screening tool can be used to evaluate a transportation measure: a switch from a conventional vehicle to an electric vehicle. The screening tool results demonstrate that the estimated cost benefits of electric vehicles varies from -$15,911 to $24,645, depending on the model of EV, miles driven annually, and externalities considered, among other factors. The cost effectiveness of EVs was improved by including avoided health costs due to reduced tailpipe emissions. More broadly, our results show that cost-effectiveness screening tools used within the electric and thermal energy sectors provide a meaningful way to assess potential gains in transportation efficiency and can be used for evaluation of other transportation efficiency measures (such as bicycle and walking infrastructure, transit, etc.). Use of such screening tools will aid in communication and collaboration between the energy and transportation sectors, while facilitating a systems-based approach to transportation planning and demand management.
  Authors: Sears, Justine; Glitman, Karen; Fanslow, Greg
  Authors: Sears, Justine; Glitman, Karen; Fanslow, Greg
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 503
  Paper Number: 13-0214
  Practice-Ready: Yes
• Traffic Capacity Models for Mini-Roundabouts in the United States: Calibration of Driver Performance in Simulation
  Abstract: The design of mini-roundabouts has been around and practiced in Europe for decades. It has been a successful and low-cost intersection configuration. Nevertheless, accessible traffic capacity models for mini-roundabouts do not exist. This study provides design recommendations and a simulation approach for capacity models of mini-roundabouts from USA data. Two typical geometries are selected that have a 24’ or 36’ approach widths typical of conventional intersections. The mini-roundabouts are best defined by the Inscribed Circle Diameter of 50’ and 75’. Mini-roundabouts are low-cost treatments using existing external boundaries of intersections. Field data are collected on Critical Gap and Headway acceptance for a similar design located in Stevensville, MD in order to calibrate a simulation. VISSIM Microsimulation software is used to model the selected prototype designs for capacity estimations. The defining feature for mini-roundabouts is the traversable central and splitter islands for large vehicles that make through or left turn movements. The linear capacity models presented, estimate the capacity of the mini-roundabouts to be lower than that of the single-lane roundabout. However the mini-roundabout has a higher capacity per square foot of land which would be an innovative solution for urban areas for increasing capacity at existing AWSC intersections at lower cost than single-lane roundabouts.
  Authors: Lochrane, Taylor W. P.; Kronprasert, Nopadon; Bared, Joe G.; Dailey, Daniel J.; Zhang, Wei
  Authors: Lochrane, Taylor W. P.; Kronprasert, Nopadon; Bared, Joe G.; Dailey, Daniel J.; Zhang, Wei
  Year: 2013
  Document Type: Paper
  Subject: Design; Operations and Traffic Management; Safety and Human Factors
  Session: 542
  Paper Number: 13-0209
  Practice-Ready: Yes
• Trip-End Facilities at Work and Bicycle Commuting in the Washington, D.C., Region
  Abstract: To encourage more bicycle commuting to work U.S. local governments have amended zoning ordinances and policies to promote more trip-end facilities for cycling and less car parking at work. This article examines the role of trip-end facilities at work, like bike parking, cyclist showers, and non-cyclist benefits, such as free car parking and transit benefits, as determinants of cycling to work. Most prior studies on trip-end facilities at work rely on hypothetical stated preference surveys of cyclists�excluding non-cyclists and not capturing mode choice for actual commutes. This analysis is based on commute data of 5,091 workers in the Washington, DC area, where commuting accounts for 41% of all bike trips. Results of logit, probit, and rare events logistic (relogit) regressions indicate that bike parking and cyclist showers are related to higher levels of bicycle commuting�even when controlling for other explanatory variables. The odds for cycling to work are greater for employees with access to both cyclist showers and bike parking at work compared to those with just bike parking, but no showers at work. Free car parking at work is associated with 69.7% smaller odds for bike commuting. Employer provided transit commuter benefits appear to be unrelated to bike commuting. Regression coefficients for control variables have expected signs, but not all are statistically significant. Greater bikeway supply, shorter commutes, and warmer weather are associated with more bike commuting. Results indicate more bicycling among commuters that are white, male, own more bicycles and fewer cars, and have higher incomes. Results are consistent with previous research and provide additional information about the role of free car parking and the potentially differential impact of bike parking vs. cyclist showers.
  Authors: Buehler, Ralph
  Authors: Buehler, Ralph
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists
  Session: 757
  Paper Number: 13-0198
  Practice-Ready: Yes
• Structural Health Monitoring for Damage Detection Under Heavy Construction Loading
  Abstract: Significant advancements in sensors and communication capabilities have increased interest in structural health monitoring as a cost effect method to monitor bridge performance and provide for pseudo real time damage detection. The objective of this paper is to present a case study regarding the use of structural health monitoring as part of a cost effective risk based approach to handling large construction loads on an existing bridge where lack of information prevented calculation of the bridge capacity. The bridge involved in this study was constructed in 1968 and provides access to a large privately held facility. As plans for implementation of a 400 million dollar expansion and renovation of the existing facility were about to start, the contractor and owner identified the existing five span bridge providing the only access to this portion of the facility as a potential impediment to the fast pace construction schedule. Limited information was available regarding the reinforcement of the existing AASHTO Type I composite beams. Based upon the available information a bridge rating of HS20-44 could be obtained, but anticipated construction loads would significantly exceed the HS20-44 design vehicle. In order to maintain the construction schedule a pseudo real time structural health monitoring program was successfully implemented to monitor bridge performance under construction loading. The monitoring system consisting of MEMS inclinometers, a data logger, digital camera, and cellular modem allowed for pseudo real time remote monitoring of bridge performance with a built in alarm notification system.
  Authors: Pavelchak, Matthew Adam; Williams, Mark Erik
  Authors: Pavelchak, Matthew Adam; Williams, Mark Erik
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 508
  Paper Number: 13-0210
  Practice-Ready: Yes
• Using Smartphone App to Support Visually Impaired Pedestrians at Signalized Intersection Crossings
  Abstract: People with vision impairment rely heavily on walking and public transit for their transportation needs. A major challenge for this population is safe crossing of intersections. As a result of the American with Disabilities Act (ADA), Accessible Pedestrian Signal (APS) systems at signalized intersections have improved significantly since 2000. However, these systems still have shortcomings for both users and municipalities, and new approaches are needed to adequately serve pedestrians with low vision. As part of our ongoing effort to develop a prototype Mobile Accessible Pedestrian Signal (MAPS) application for the blind and visually impaired, we interviewed ten blind and low-vision people to better understand what types of information they use at intersection crossings and to identify information types that could assist them. With these survey results, a MAPS system was developed that provides signal and intersection geometry information to smartphone users at signalized intersections. User interaction is via simple tactile input (single or double-tap) and Text-To-Speech (TTS) technology. Field experiment at two signalized intersections was conducted among 18 visually impaired participants to validate the use and functioning of the MAPS system in real-world application. The purpose is to identify if the smartphone app could effectively provide geometry and signal timing information and thus provide decision support for the visually impaired pedestrians. Objective and subjective measures were developed to evaluate the performance of visually impaired users while using the MAPS. Participants reported that the MAPS system provides helpful geometry information (82%) and helpful signal information (59%).
  Authors: Liao, Chen-Fu
  Authors: Liao, Chen-Fu
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 459
  Paper Number: 13-0231
  Practice-Ready: Yes
• Mitigating Financing of Major Public Infrastructure Projects: Bidding by Net Present Value
  Abstract: The construction of major public infrastructure projects requires long term investment of substantial amounts of working capital and the financing costs is a major risk that is mostly shouldered by the contractors. The financing capabilities and high level of risk results in limiting competition and the higher financing cost will eventually be paid by the project owner and ads up to the total project capital cost. This paper will examine the financing cost of major public projects and will explorer methods that can be adopted to shift the financing burden and the risk to the party that is most capable to manage it. We will introduce methods to measure project cost elements that are contributing to the financing cost of the project. We will illustrate that the inclusion of the time-value of money in the bid evaluation process is the vehicle for measuring the financing cost of the project that allows equitable shifting of the financing risk to the owner, thus reducing the financing cost, increasing competition and reducing total project capital cost. The entire contracting methodology, financing and construction process in the twenty first century requires a fresh approach that ultimately leads to the best possible project for the best possible price. Letting contracts out based upon the Net Present Value (NPV) is just such an approach.
  Authors: Abadi, Djalil H.
  Authors: Abadi, Djalil H.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design
  Session: 244
  Paper Number: 13-0249
  Practice-Ready: Yes
• Revisiting the Cycle Length--Lost Time Question with Critical Lane Analysis
  Abstract: During oversaturation, the objective in signal operations is to maximize throughput in order to keep traffic moving. The fact that lost time shrinks as a proportion of total operating time as cycle length increases has long been used as an argument for programming longer cycle lengths into traffic signals. This paper revisits the concept of critical lane analysis to calculate throughput and applies the technique to data collected at an intersection in Indianapolis that is regularly oversaturated during the PM peak hour. Traffic volumes were measured from over 10 weeks while different cycle lengths were tested at the intersection, ranging from 80 to 135 seconds. Somewhat surprisingly, during saturated conditions, no clear improvement in the sum of critical lane throughput was observed, even when the cycle length increased by over 50%. In fact, there was a slight reduction in the total critical lane sum volume at 135 seconds. The findings concur with a recent simulation study by Denney et al.. We attribute the reduction in throughput at the longer cycle length to the reduction of saturation flow, s, during long green times reported in recent studies, and demonstrate that time-dependent functions of s could change forecasts of throughput as a function of cycle length to better reflect field observations. Additionally, the critical lane analysis methodology has applications for agencies to evaluate and rank intersections within corridors as under, near, or over saturation.
  Authors: Day, Christopher M.; Sturdevant, James R.; Li, Howell; Stevens, Amanda; Hainen, Alexander Michael; Remias, Stephen Matthew; Bullock, Darcy M.
  Authors: Day, Christopher M.; Sturdevant, James R.; Li, Howell; Stevens, Amanda; Hainen, Alexander Michael; Remias, Stephen Matthew; Bullock, Darcy M.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 261
  Paper Number: 13-0250
  Practice-Ready: Yes
• Evaluation of Long-Lasting Perpetual Asphalt Pavement Using Life-Cycle Cost Analysis
  Abstract: In 2006, the Oklahoma Department of Transportation (OKDOT) sponsored work at the National Center for Asphalt Technology (NCAT) Pavement Test Track to compare the performance of two sections that were designed to determine the thickness required to obtain a perpetual pavement. One section (Section N9) was designed to be a perpetual pavement (14 inches thick) and the thickness of the other section was reduced to 10 inches (based on AASHTO 1993 design guide) to see how well it performed and to help identify the thickness needed for a perpetual pavement. This paper presents a life-cycle cost analysis (LCCA) to quantify the benefits of building the perpetual pavement section compared to the long term cost of the thinner section. LCCA was conducted using RealCost 2.5, which is available through FHWA, to determine quantitative estimates of construction schedule, work zone user costs, and agency costs for initial construction and rehabilitation activities. The perpetual pavement section was found to have a lower life-cycle cost than the conventional pavement section and provide better service to highway users. Furthermore, to help better planning for future preservation study the estimated present serviceability rating (PSR) as a function of international roughness index (IRI) for two different designs (perpetual and non-perpetual) was carefully evaluated. The findings of surface measurements for both sections clearly demonstrate a difference between perpetual and conventional pavement serviceability for a given level of roughness and accumulated traffic. These results are also helpful to assess the improvement of conventional pavement after each rehabilitation treatments.
  Authors: Sakhaeifar, Maryam; Brown, E. Ray; Tran, Nam; Dean, Jeff
  Authors: Sakhaeifar, Maryam; Brown, E. Ray; Tran, Nam; Dean, Jeff
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 239
  Paper Number: 13-0330
  Practice-Ready: Yes
• Cádiz Bay Tram-Train: First Experience over Spanish Conventional Tracks
  Abstract: Tram-train systems are an evolution of light rail in which the vehicle can run on the urban tracks that have been implemented specifically for the system, but it can enter, at a given point, into conventional railway tracks that have been implemented for and are used by conventional railway vehicles. In this way, urban and metropolitan light rail services can be extended further away from the city center, avoiding part of the cost of new infrastructure, and offering a seamless link between the urban center and the suburban areas.The fact of running on different kinds of tracks, with different types of superstructure and geometric characteristics, as well as different standards in relation to safety and other subjects, makes the design of tram-train systems especially complex. The aim of the present paper is to describe some of the most important technological challenges for the implementation of Cádiz Bay tram-train. It is the first tram-train developed over Spanish conventional railway tracks belonging to ADIF (Administrador de Infraestructuras Ferroviarias, Administrator of Railway Infrastructures). Some of the main technological features of this tram-train are: 1,668 mm track gauge, with the possibility of a future transformation to 1,435 mm; a partially low-floor tram-train vehicle, to cope with the two kinds of stations/stops (urban and railway ones); a tram-train wheel with wide flange, to match the conventional railway tracks, which leads to wide-grooved rails in the new urban stretches of the network; dual-voltage vehicle 3000-750 V dc, etc.
  Authors: Novales, Margarita; Conles, Emilio
  Authors: Novales, Margarita; Conles, Emilio
  Year: 2013
  Document Type: Paper
  Subject: Public Transportation
  Session: 415
  Paper Number: 13-0334
  Practice-Ready: Yes
• Effects of License Plate Attributes on Automatic License Plate Recognition
  Abstract: This paper describes an experiment designed to develop a comprehensive and thorough understanding of the readability of North Carolina’s license plates with an Automatic License Plate Recognition system. This research focused on law enforcement applications and utilized two infrared camera systems for data collection in a controlled environment involving over 900 license plates. The field test was conducted in a controlled environment under the following settings and conditions: 25 mph test vehicle, nighttime evaluation, closed test track, 40’ spacing of license plates, 9’ lateral offset between license plates and camera, standard-issue and specialty plate types, standard syntax and personalized plates, varying license plate age and condition. The key finding of this research project is that the current, standard issue, blue ink license plate has the highest capture and read rates among plates tested in this study. Factors which decreased the capture and read rates were personalized syntax, specialty license plates, and the presence of stacked characters on a specialty license plate.
  Authors: Findley, Daniel J.; Cunningham, Christopher M.; Chang, Jeffrey Chiaming; Hovey, Kyle Andrew; Corwin, Michael Allan
  Authors: Findley, Daniel J.; Cunningham, Christopher M.; Chang, Jeffrey Chiaming; Hovey, Kyle Andrew; Corwin, Michael Allan
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0281
  Practice-Ready: Yes
• Innovative Approaches for an Interactive Stated-Choice Survey
  Abstract: Stated preference surveys provide an excellent source of information for the development and targeted implementation of transport planning measures. This paper describes two innovative methods used in a study of road pricing’s impact on travel behavior in Austria. First, the research used an innovative process to generate realistic route choice alternatives for use in the survey. These alternatives were generated using online resources (e.g. Google Maps) and created alternatives that were familiar to the survey respondents. Second, the research used three different methods for data collection: tablet computer assisted interviews, web assisted interviews and traditional pencil and paper interviews. The use of these different methods helped the researchers obtain a representative sample of the Austrian population. While tablet-assisted interviews appealed to the younger generation, older people were incorporated with the pen-and-paper method. Additionally, via systematic sampling people from “hard-to-reach” groups became accessible. An important benefit of using the tablet-based data collection was that survey participant demographic data was available in real time enabling the survey manager to direct surveyors to target underrepresented groups immediately. The tablet computers also improved data quality and slightly increased willingness to participate in the survey.
  Authors: Reiter, Thomas; Völkl, Andrea; Fellendorf, Martin
  Authors: Reiter, Thomas; Völkl, Andrea; Fellendorf, Martin
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 615
  Paper Number: 13-0272
  Practice-Ready: Yes
• Equipment Replacement Decision Making: Challenges and Opportunities
  Abstract: A primary objective for equipment managers is to replace the right equipment at the right time and at the lowest overall cost. To help accomplish this task, a theoretically sound and practically feasible equipment replacement optimization methodology has been developed so that a significant amount of money can potentially be saved. In this paper, the challenges and opportunities associated with equipment replacement decision making are discussed in detail. First, a comprehensive review of the state-of-the art and state-of-the practice literature on the equipment replacement optimization (ERO) problem is conducted. Second, the developed ERO software components and functionalities are presented. Third, several challenges faced by the research team during the ERO software development process are described including statistical modeling (purchase cost forecasting and down time cost estimating), optimization (in terms of stochastic dynamic programming (SDP) and ERO under budget constraints), and software implementation (particularly for the SDP approach) challenges. Detailed information as to how such challenges have been overcome and turned into opportunities using the current Texas Department of Transportation (TxDOT) data is also presented. Fourth, real opportunities and the promising future for ERO decision making tools are discussed and supported by comprehensive numerical results and their implications. Finally, a summary of the information presented and details about future research directions are also given.
  Authors: Fan, Wei; Gemar, Mason David; Machemehl, Randy B.
  Authors: Fan, Wei; Gemar, Mason David; Machemehl, Randy B.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Vehicles and Equipment
  Session: 770
  Paper Number: 13-0326
  Practice-Ready: Yes
• Relationship Between Tire-Pavement Interaction Noise and Surface Characteristics in 2009 Pavement Test Track Cycle
  Abstract: The interest in quieter pavements has been driven largely by public awareness that altering the surface can affect traffic noise levels. The objective of this research was to utilize two methods for measuring tire-pavement noise to assess which pavement surface characteristics have the greatest influence on noise generation. The National Center for Asphalt Technology (NCAT) test road, with four different pavement surface family groups, was used to test and analyze noise from tire-pavement interaction. The tire-pavement noise was measured in a novel test approach using a surface microphone from different types of sections in the Test Track. Testing was conducted on four major family groups of superpave fine and coarse graded, open-graded friction course (OGFC) and stone matrix asphalt (SMA) mixes from 2009 NCAT Test Track research cycle to evaluate changes over time. The results show that the noise levels vary widely according to pavement surface type. The effects of pavement properties including the air void content, gradation properties, roughness, texture, pavement stiffness and age have been evaluated on one-third octave band noise levels. The evaluation confirmed that macrotexture increases the low frequency noise and higher air void content reduce the high frequency noise level, while other surface characteristics found to have less influence on noise levels. The content of this study should be of immediate interest to pavement engineers and others concerned with pavement design and construction to determine appropriate quieter pavement surface.
  Authors: Sakhaeifar, Maryam; Liao, Gong-yun; Waller, Brian
  Authors: Sakhaeifar, Maryam; Liao, Gong-yun; Waller, Brian
  Year: 2013
  Document Type: Paper
  Subject: Environment; Pavements
  Session: 814
  Paper Number: 13-0328
  Practice-Ready: Yes
• Network Connectivity and Low-Stress Bicycling
  Abstract: For bicycling networks to attract the mainstream population, a critical attribute is low-stress connectivity, that is, providing routes between people’s origins and destinations that do not require cyclists to use links that exceed their tolerance for traffic stress, and that do not involve an undue level of detour. A set of criteria are proposed by which road segments, intersection approaches, and intersection crossings can be classified into four levels of traffic stress (LTS), of which LTS 2, based on Dutch bikeway design criteria, represents the traffic stress that most adults will tolerate. As a case study, every street in San Jose, California was classified by LTS. Maps in which only lower stress links are displayed reveal a city divided into islands within which low-stress bicycling is possible, but separated from one another by barriers that can only be crossed using high stress links. Such maps can help guide network development by revealing barriers such as arterial streets that lack intersections with both safe crossing provision and low-stress approaches. A summary measure of connectivity, the connectivity ratio for a given LTS, is the fraction of daily trips connected at that LTS. For San Jose, the fraction of work trips up to 6 miles long that are connected at LTS 2 is 4.7%. This figure would almost triple by implementing a modest slate of improvements aimed at connecting low-stress streets and paths with each other.
  Authors: Furth, Peter G.; Mekuria, Maaza
  Authors: Furth, Peter G.; Mekuria, Maaza
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0427
  Practice-Ready: Yes
• Virginia Tech Comprehensive Power-Based Fuel Consumption Model: Model Validation and Calibration Considerations
  Abstract: A power-based vehicle fuel consumption model, entitled the Virginia Tech Comprehensive Power-based Fuel Consumption Model (VT-CPFM) that was developed in an earlier publication is validated against in-field fuel consumption measurements. The study demonstrates that the VT-CPFMs calibrated using the EPA city and highway fuel economy ratings generally provide reliable fuel consumption estimates with a coefficient of determination in the range of 0.96. More importantly, both estimates and measurements produce very similar behavioral changes depending on engine load conditions. The VT-CPFMs are demonstrated to be easily calibrated using publically available data without the need to gather in-field instantaneous data.
  Authors: Park, Sangjun; Rakha, Hesham; Ahn, Kyoungho; Moran, Kevin
  Authors: Park, Sangjun; Rakha, Hesham; Ahn, Kyoungho; Moran, Kevin
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-0461
  Practice-Ready: Yes
• Comparative Analysis of U.S. Environmental Protection Agency Operating Mode Distribution Generator with Real-World Operating Mode and Emissions Data
  Abstract: In June 2012, the Environmental Protection Agency (EPA) released the “Operating Mode Distribution Generator” (OMDG) a tool for developing an operating mode distribution as an input to the Motor Vehicle Emissions Simulator model (MOVES). The tool converts basic information about traffic operations – idle time, grade, and average speed – into an operating mode distribution. This tool is designed to make project-level analyses for CO and PM hot-spots easier to conduct with basic traffic activity data.This paper compares the operating mode distributions obtained from this tool with those measured on a vehicle instrumented with the Total On-Board Tailpipe Emissions Measurement System (TOTEMS). TOTEMS generates a wealth of data, including a vehicle’s speed, idle time, and link grade – all of the inputs necessary to run the OMDG. The comparison is made for 4 signalized intersections on an urban arterial in Burlington, Vermont. This analysis shows that the OMDG, when compared to 31 test runs of an instrumented vehicle, was more accurate under circumstances of no to low grade and higher congestion (higher stop time). Estimation inaccuracies are most critical for specific operating modes -- for CO under high VSP conditions; for PM10 under braking conditions (i.e. VSP <0). This investigation has developed a method for quantitatively evaluating tools designed to simplify a mobile emissions analysis. Future work will include the development of models for estimating operating modes of a traffic stream using traffic microsimulation and highlighting those parameters that are most critical to calibrate for obtaining an accurate operating mode distribution estimate.
  Authors: Chamberlin, Robert; Holmen, Britt A.; Talbot, Eric; Sentoff, Karen M.
  Authors: Chamberlin, Robert; Holmen, Britt A.; Talbot, Eric; Sentoff, Karen M.
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-0387
  Practice-Ready: Yes
• Design, Construction, and Performance of Mastic Asphalt Concrete for Orthotropic Bridge Decks
  Abstract: Mastic asphalt concrete is traditionally applied to the steel deck pavement for an orthotropic bridge. Since mastic asphalt concrete is poured into place and required no compaction, it is essential to develop the material especially for paving applications. The purpose of this research project is to characterize the engineering properties of mastic asphalt concrete and analyze the immediate and long-range performance of the paving system. Test results in the laboratory indicated that an increase in the Trinidad Lake Asphalt (TLA) content led to an increase in the softening point of mastic asphalt concrete. Morphology obtained from scanning electron microscopy showed that asphalt, TLA and mineral fillers were uniformly mixed. The properties and relative proportions of binders and mineral fillers significantly affected the engineering behavior of mastic asphalt concrete. The surface characteristics of aggregate were shown to play a key role in rutting resistance. Testing procedures were developed to design a mastic asphalt mixture for field construction. Practical experiences on the production and construction practices of mastic asphalt concrete were provided. The performance of mastic asphalt concrete was evaluated.
  Authors: Chen, Jian-Shiuh; Chen, Shih-Fan; Liao, Min-Chih
  Authors: Chen, Jian-Shiuh; Chen, Shih-Fan; Liao, Min-Chih
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Materials
  Session: 651
  Paper Number: 13-0404
  Practice-Ready: Yes
• Variable Speed Limit Control Based on Extended Link Transmission Model
  Abstract: In this paper, the link transmission model (LTM) is extended to include the effects of variable speed limits(VSL) and consequently to provide variable speed limit control for traffic networks modeled by LTM. The LTM has recently been developed for route assignment, but in this paper the LTM is modified to be used for control purposes. By this we achieve a model that provides a balanced trade-off between accuracy and computational complexity, and hence it is useful for on-line model-based traffic control.Nevertheless, the extension of the model for ramp metering and speed limit control needs careful attention. Since the LTM lacks explicit velocity equations focus is on other potential sources that could imitate the influences of VSL. The delays inside the model are manipulated in order to achieve the mentioned goal. Moreover, we take into account different situations that may occur in reality based on changes in VSL and different traffic conditions. Finally, the total extensions are verified using simulation and real data. To this aim, the VSL extension integrated in the LTM is verified using simulations for a benchmark case study (in order to show performance of the extended LTM clearly). Next, the LTM is calibrated by real data collected from the A12 Freeway in The Netherlands. The optimal parameters of the model are identified using a global optimization method. Comparison with real data from a period of time that VSL installed on the freeway are active, shows acceptable performance of the total extended and calibrated LTM.
  Authors: Hajiahmadi, Mohammadreza; Corthout, Ruben; Tampere, Chris; De Schutter, Bart; Hellendoorn, Hans
  Authors: Hajiahmadi, Mohammadreza; Corthout, Ruben; Tampere, Chris; De Schutter, Bart; Hellendoorn, Hans
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 497
  Paper Number: 13-0409
  Practice-Ready: Yes
• Midwest Guardrail System Without Blockouts
  Abstract: The Midwest Guardrail System (MGS) has been shown to provide exceptional redirective capability in standard and many special applications. However, the roadway width required to install a guardrail system with a blockout is not always available. In response, a non-proprietary non-blocked MGS was developed and successfully crash tested according to the testing standards established in the Manual for Assessing Safety Hardware (MASH). Results from the 1100c small car and 2270p pickup truck tests are compared between the blocked and non-blocked version of the MGS, and it is concluded that the blocked MGS performs better than the non-blocked MGS. As a result, it is recommended that the non-blocked MGS only be used in places where roadway width is a limiting parameter. But, if width is not restricted, it is still recommended to use a blockout as designated in the design drawings of the standard MGS.
  Authors: Reid, John D.; Faller, Ronald K.; Bielenberg, Robert; Lechtenberg, Karla A.
  Authors: Reid, John D.; Faller, Ronald K.; Bielenberg, Robert; Lechtenberg, Karla A.
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 440
  Paper Number: 13-0418
  Practice-Ready: Yes
• Case Studies of Early Contractor Design Involvement to Expedite the Delivery of Emergency Highway Projects
  Abstract: In the past decade, events such as Hurricanes Katrina and Irene and the sudden collapse of the Interstate 35W Bridge in Minnesota forced state departments of transportation (DOT) to step into the public spotlight and implement expedited procurement procedures to restore vital links in the transportation network with the media scrutinizing their work every night on the evening news. This paper presents the results of case studies of Florida, Maine, Minnesota, New York and Utah where the DOT brought the construction contractor into the design process as the primary means to expedite the delivery of emergency projects. The case studies include the use of indefinite delivery/indefinite quantity (IDIQ), construction manager/general contractor (CMGC) and design-build (DB) contracts as mechanism to gain substantive contractor input on materials, means, and methods during design. The paper concludes that completing the design is the first obstacle to surmount in emergency procurements and the surest tool to expedite emergency project delivery is to design around immediately available materials, equipment, and proven accelerated construction methods, information that is best developed by the contractor that will eventually complete the construction. The paper recommends that agencies develop expedited procurement procedures for ID/IQ, CMGC, and DB contracts before emergencies occur and furnishes case study information for specific methods for streamlining routine procurement procedures.
  Authors: Gransberg, Douglas D.
  Authors: Gransberg, Douglas D.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design
  Session: 244
  Paper Number: 13-0403
  Practice-Ready: Yes
• Comparative Analysis of Car-Following Models for Emissions Estimation
  Abstract: Recent studies indicated that the accuracy of the emission estimation in a traffic simulation model can hardly be improved by using the traditional model calibration approaches. Instead, its internal mechanism in depicting the second-by-second vehicle activities needs to be investigated. Since the car-following model is the core component of a traffic simulation model, this paper attempts to conduct a comparative study of car-following models on their effects on the explanatory parameter of vehicle emissions - vehicle specific power (VSP) distribution. OVM, GFM, FVDM, Wiedemann, and Fritzsche car-following models are selected for the analysis. Massive filed car-following trajectories are collected and a numerical simulation method is designed for each car-following model to generate its vehicle trajectories and the speed-specific VSP distributions. By comparing VSP distributions collected from the field and generated by car-following models, it is found that OVM and GFM models generate unrealistic VSP distributions, which will lead to significant emission estimation errors. By adding the variable of positive velocity difference, The FVDM molde can improve the accrucy of the VSP distribution and emission estimation effectively. The VSP distribution of Wiedemann model differs largely from the field data, which overestimates the peak VSP fraction and the fractions in aggressive driving modes. The Fritzsche model produces consistent VSP distributions with the field ones. It is also found that the speed-specific VSP distribution is highly correlated with the acceleration distribution. Therefore, improving the accuracy of speed-specific acceleration distribution is an effective measure to improve the accuracy of the VSP distribution, thus the emission estimation of the car-following models.
  Authors: Song, Guohua; Yu, Lei; Xu, Long
  Authors: Song, Guohua; Yu, Lei; Xu, Long
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-0460
  Practice-Ready: Yes
• Experiences of Two Colorado Transportation Agencies with Their First Construction Manager-General Contractor Projects
  Abstract: Construction Manager/General Contractor (CMGC) project delivery system is beginning to be recognized as an effective way of accelerating the delivery of transportation projects and gaining popularity among transportation agencies. This research documents the experiences of two transportation agencies in Colorado and provides information with respect to the practices utilized by each agency in implementing the CMGC project delivery system for the first time. The first project is the Eisenhower-Johnson Memorial Tunnel Motor Control Cabinets Replacement project whose agency owner is the Colorado Department of Transportation. The second project is West Rail Line project whose agency owner is the Regional Transportation District. To provide findings that can benefit transportation agencies, researchers used multiple sources of information including structured in-depth interviews, questionnaires completed by key individuals working in the investigated projects, and published documents about the investigated projects. The findings provide a broad perspective on the different practices in implementing this project delivery system; and are presented under eight different areas: (i) rationale for choosing the particular project to utilize the CMGC project delivery system, (ii) procurement phase, (iii) preparation of the agency for the CMGC project, (iv) design contract for the CMGC project, (v) guaranteed maximum price and contingency, (vi) subcontracts, (vii) preconstruction services, and (viii) lessons learned. It was concluded that while both owners are Colorado transportation agencies, they utilized significantly different practices in implementing the CMGC project delivery, which eventually resulted in differences in opinion with respect to the potential of this system to be used in subsequent projects.
  Authors: Ozbek, Mehmet Egemen; Lopez Del Puerto, Carla; Gransberg, Douglas D.
  Authors: Ozbek, Mehmet Egemen; Lopez Del Puerto, Carla; Gransberg, Douglas D.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design
  Session: 244
  Paper Number: 13-0466
  Practice-Ready: Yes
• Effects of Queue Jumpers and Transit Signal Priority on Bus Rapid Transit
  Abstract: Preferential treatments for transit are needed for high-occupancy transit vehicles to improve their operations. However, these treatments are often not effective in saturated traffic conditions when transit operates in mixed traffic. Additional Right-of-Way (ROW) for transit at intersections can be achieved with Queue Jumpers. They allow buses to bypass the waiting queues by using queue jumper lanes and getting an early green signal. The goal of this paper is to evaluate individual and combined effects of Queue Jumpers and Transit Signal Priority (TSP) on performance of a Bus Rapid Transit (BRT) system and vehicular traffic along 3500 S in West Valley City, Utah. Four VISSIM microsimulation models were developed for evaluation: the existing scenario without special treatments for transit (Base), the QJ scenario that introduced Queue Jumpers only, the TSP scenario that implemented TSP only, and a combination of Queue Jumpers and TSP (QJ & TSP). The implementation of any transit strategy resulted in significant improvements in BRT operations. The QJ & TSP scenario yielded highest benefits: 13-22% reduction in BRT travel times, better corridor progression, lower intersection delays and number of stops, increased speed (22%), and better travel time reliability and headway adherence. Transit treatments did not affect private traffic along the corridor. These strategies, however, had certain impacts on side streets. QJ & TSP scenario increased average delays for cross-street traffic by 15%. However, with small improvements in QJ and TSP settings, the combination of the two strategies can be most beneficial and highly desirable for implementation.
  Authors: Reza, Zahid; Zlatkovic, Milan; Stevanovic, Aleksandar
  Authors: Reza, Zahid; Zlatkovic, Milan; Stevanovic, Aleksandar
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 496
  Paper Number: 13-0483
  Practice-Ready: Yes
• Long-Term Investigation into the use of New Rapid Hardening Cement for Controlled Low-Strength Materials to be Employed in Pavement Applications
  Abstract: Controlled low strength materials (CLSMs) are engineered, cement based materials of growing interest in all trench backfilling and bedding applications where low stiffness, strength and density are required. Although 50 years have passed since its first application, the technology has been the source of continuous innovation. The challenge today concerns the excessive and undesirable long-term gain in strength of current CLSMs available on the market which leads to difficulties in the event of future removal and to unbalanced stress strain behavior with surrounding soils.In this investigation, the authors present a long-term laboratory study aimed at the creation of new formulations for pavement applications with the objective of avoiding or limiting any gain in stiffness and resistance over time. For this purpose, a rapid hardening cement has been used as a substitute for Portland cement. The particular formulation of cement adopted presents many advantages in terms of rapid set, high early strength development and insignificant gain in strength over long periods. All the mixtures studied were subjected to static and dynamic triaxial tests taking the mechanical characteristics of a reference granular soil as the mix design target for new CLSM formulations. The results deriving from the use of different admixtures and mixing procedures in terms of mixing time, batching sequence and type of mixer were also investigated.
  Authors: Bertola, Federica; Bassani, Marco; Canonico, Fulvio; Bianchi, Manuela
  Authors: Bertola, Federica; Bassani, Marco; Canonico, Fulvio; Bianchi, Manuela
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 664
  Paper Number: 13-0509
  Practice-Ready: Yes
• Reclaiming the Right-of-Way: Best Practices for Implementing and Designing Parklets
  Abstract: Road space comprises a significant amount of acreage in US cities, and at least since the last century, it has been the exclusive domain of the automobile. Many cities are beginning to use innovative techniques and design treatments, such as parklets, to reclaim some of the excess road space for pedestrian uses. Parklets emerge from the low-cost conversion of small and underutilized residual spaces originally devoted to cars into spaces for the passive or active recreation of people. The idea of the parklet in its current expression emerged in San Francisco in the form of temporary, one-day installations intended to extend the social life and pedestrian space of the sidewalk into parking spaces. Cities including Philadelphia, Long Beach, Oakland, and many others have initiated or are in the process of planning parklet programs. This research examines how cities have implemented their parklet programs including considerations for departments involved, understanding permitting issues, and setting design guidelines. Additionally, the research examines specific sites to investigate how designers have translated design guidelines into safe, comfortable, and well-used spaces for people to enjoy. Interviews with city staff, designers, and business owners provide evidence towards best practices and recommendations for anyone wanting to use this innovative practice for transforming space within the right-of-way.
  Authors: Brozen, Madeline; Loukaitou-Sideris, Anastasia
  Authors: Brozen, Madeline; Loukaitou-Sideris, Anastasia
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Planning and Forecasting; Policy
  Session: 682
  Paper Number: 13-0464
  Practice-Ready: Yes
• Estimation of Operational Benefits of Slow Vehicle Turnouts on Rural Highways in Alaska
  Abstract: This paper draws on the results from previous research regarding two-lane highway operations and platooning characteristics to develop an estimate of the operational benefit that will be realized when slow vehicle turnouts are constructed on a 70-mile section of the Sterling Highway on the Kenai Peninsula in Alaska. Speed and volume data were collected at three sites in the study area to quantify the existing conditions. Three measures of effectiveness are presented: the distribution of platoon sizes, the percent following (defined as the percent of all vehicles that are following another vehicle at time headways of 3 seconds or less), and the percent impeded. Percent impeded is calculated as a modification of the percent following measurement to account for vehicles that are following, but are traveling at their desired speed, and are therefore not being impeded.Future operations after the installation of the proposed slow vehicle turnouts are estimated by modifying the percent following to account for lead vehicles pulling into the slow vehicle turnouts and allowing others to pass. The percent impeded was then calculated for this modified value for percent following. A sensitivity analysis was performed to show how percent impeded was affected by differences in the percentage of lead vehicles who use the slow vehicle turnouts to let others pass. It is concluded that the slow vehicle turnouts will provide a measurable benefit to operations on the subject highway.
  Authors: Dunham, Connor; Bowie, Jeanne; Kinney, James Randall
  Authors: Dunham, Connor; Bowie, Jeanne; Kinney, James Randall
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 405
  Paper Number: 13-0555
  Practice-Ready: Yes
• Bus Operator Perceptions of Safety Risks
  Abstract: This paper presents the results of a survey of TriMet bus operators addressing safety risks in their work. Surveyed risk factors were organized into five categories: vehicle design and condition; route layout; operating conditions; fatigue; and stress. Operators perceived fatigue and stress to be the greatest sources of safety risk, with split shifts, schedule pressures, passenger distractions, and negligence of other roadway users being the primary contributors to these conditions. Operators were also surveyed on the frequency and nature of “close calls,” with two-thirds of the operators indicating that such incidents occurred at least weekly and most often involved being cut off by other roadway users. Operators endorsed high visibility enforcement initiatives to improve safety, focusing primarily on negligent behavior. Other operator-recommended changes addressed scheduling practices and the need for more public information and outreach on safety risks.
  Authors: Strathman, James; Callas, Steve; Kwon, Sung Moon
  Authors: Strathman, James; Callas, Steve; Kwon, Sung Moon
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 712
  Paper Number: 13-0564
  Practice-Ready: Yes
• Seismic Retrofit of San Francisco BART Aerial Stations
  Abstract: Considering the high risk of earthquakes in the San Francisco Bay Area and the essential role of the Bay Area Rapid Transit (BART) system in the region, the BART Earthquake Safety Program (ESP) has attracted great public attention from the beginning. This paper covers the seismic evaluation and retrofit of a total of eleven aerial stations within the BART System. All eleven stations are being retrofitted to meet Safety Performance requirements; and three stations have been additionally retrofitted to meet Operability Performance requirements. The details of the analysis approaches, seismic vulnerability of as-built stations, and retrofit measures proposed for the BART retrofit effort are presented in this paper. It was found that existing bent cap beams and footing caps are insufficient to resist the overstrength demands from the columns. Joints between columns and bent caps and joints between columns and footings are required to be strengthened as well. By various retrofit measures, including bent cap bolsters, in-fill walls, column FRP wrapping, footing partial overlays, and footing enlargements, the stations can be upgraded to achieve Safety and Operability Performance requirements.
  Authors: Wang, Huanzi; Ng, Shirley; Abdel-Karim, Ahmad M; Weston, Dan
  Authors: Wang, Huanzi; Ng, Shirley; Abdel-Karim, Ahmad M; Weston, Dan
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: 499
  Paper Number: 13-0566
  Practice-Ready: Yes
• Water Spray Endurance Test Investigation: Evaluation of Highway Anti-icer Performance Under Freezing Precipitation
  Abstract: A modified Water Spray Endurance Test (WSET) was adapted from the SAE Standard AS5901B and used to study the anti-icing endurance of a variety of sodium chloride-based highway anti-icer liquids. Freezing precipitation immediately forms rime ice on surfaces with no anti-icer treatment. On surfaces treated with anti-icer, freezing precipitation goes through a series of stages, initially forming a liquid brine layer, then forming non-adherent glaze ice, and finally forming rime ice. The modified WSET test was used to study the effect of a variety of additives in NaCl anti-icing liquids. High molecular weight organic polymer additives were found to strongly inhibit the onset of rime ice formation. The delay in the onset of rime ice formation caused by anti-icers is postulated to be due to an enhancement of surface melting, increasing the size of the quasi-liquid layer at the ice surface and favoring glaze rather than rime ice formation until the anti-icer has been sufficiently diluted. The same surface melting enhancement caused by anti-icer chemicals may also be responsible for the observed effectiveness of low concentrations of anti-icer at preventing ice adhesion to pavement surfaces. In this context, the use of the modified WSET test to evaluate rime ice growth rates is discussed as a possible way to compare the relative precipitation resistance (and therefore “effective lifetime”) of different anti-icer formulas.
  Authors: Koefod, Scott
  Authors: Koefod, Scott
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Safety and Human Factors
  Session: 204
  Paper Number: 13-0517
  Practice-Ready: Yes
• Evaluation of Innovative Bicycle Facilities in Washington, D.C.: Pennsylvania Avenue Median Lanes and 15th Street Cycle Track
  Abstract: Two innovative bicycle facilities were installed in Washington, DC during 2010 by the District Department of Transportation (DDOT): buffered center median bicycle lanes on Pennsylvania Avenue Northwest and a two-way cycle track on 15th Street Northwest. Both facilities include dedicated road space with buffers between bicyclists and motor vehicles, signal control, and signs and pavement markings. The facilities were designed to provide increased safety, comfort, and convenience for cyclists. This paper presents the results of a comprehensive study that evaluated the facilities to understand how well they work for cyclists, motorists, and pedestrians in terms of safety, level of service (LOS), behavior, and attitude. The evaluation found that bicycle LOS improved and that bicycle volumes on those corridors nearly quadrupled, well above the rate of city-wide bicycle use. Motor vehicle LOS was largely unaffected. Signal progression was mixed for bicyclists, with contraflow travel on the one-way portion of 15th Street and traveling against the dominant travel direction on Pennsylvania Avenue showing the worst travel time performance. While bicycle crashes increased on both facilities, the crash rate remained similar on 15th Street; Pennsylvania Avenue saw a higher crash rate. In surveys of all travelers on the corridor (bicyclist, motorist, pedestrian) and nearby residents, the perception of the lanes is generally positive for all users and the lanes are seen as a positive addition to the community.
  Authors: Goodno, Mike; McNeil, Nathan Winslow; Parks, Jamie; Trainor, Stephanie Dock
  Authors: Goodno, Mike; McNeil, Nathan Winslow; Parks, Jamie; Trainor, Stephanie Dock
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Planning and Forecasting; Policy; Public Transportation
  Session: 347
  Paper Number: 13-0519
  Practice-Ready: Yes
• Examining Estimation Bias and Efficiency for Pseudo Panel Data in Travel Demand Analysis
  Abstract: Pseudo panel data have been increasingly applied in travel demand analysis to investigate the long-run travel demand when genuine panel data are unavailable. However, conventional estimation techniques have been used typically without a careful consideration to some unique properties of pseudo panel data. This paper shows that ignoring properties such as time-varying cohort effects, a small number of constructed cohorts, large between-group variance, and trade-offs between cohort sizes and number of cohorts potentially leads to estimation bias or inefficiency not observed in genuine panel data. The methodology of a Monte Carlo experiment is used with scenarios that are designed to generate, under conditions of limited observations, various data possessing pseudo panel data characteristics, and evaluates the performances of various estimators using the simulation results. The main research findings are that the large between-group variation of the exogenous variable and the variance of fixed group effects in pseudo panel data are the primary causes of estimation bias and inefficiency. Other factors including the cohort size and potential non-spherical errors have a smaller impact on the estimators’ performances. An empirical application using Sydney Household Travel Survey data is also presented to illustrate the simulation findings.
  Authors: Tsai, Chi-Hong; Leong, Waiyan; Mulley, Corinne; Clifton, Geoffrey Tilden
  Authors: Tsai, Chi-Hong; Leong, Waiyan; Mulley, Corinne; Clifton, Geoffrey Tilden
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 615
  Paper Number: 13-0538
  Practice-Ready: Yes
• Quantifying Key Errors in Household Travel Surveys
  Abstract: Identifying and minimizing potential errors in household travel surveys can facilitate collecting more representative and accurate data. This paper presents how sampling, non-coverage, non-response, and measurement errors work their ways into surveys through a comparison of two recent travel surveys with census data. The 2009 National Household Travel Survey (NHTS) Add-On in Virginia was implemented using a comprehensive survey instrument and Random Digit Dialing (RDD). The 2008 National Capitol Region Household Travel Survey collected behavioral data with a concise instrument, while adopting Address-Based (ADD) sampling. Focusing on a common area of Northern Virginia, this study examined differences in socio-demographics and travel behavior of the extracted samples (N=597 and N=3,581, respectively). Results show that the ADD method collected data on more single-person households, younger individuals, and Hispanics/Mexicans, which are generally identified as hard-to-reach groups. A comparison of the two unweighted samples with census data shows that the ADD sample was more representative of the population and area, partly because of the inclusion of mobile phone only households (28%), which are not covered in RDD. To quantify a measurement error, rigorous statistical models were estimated in terms of reported trip frequency. Results show that NHTS captured 10% more trips, partly due to diary instructions and the presence of walking/biking questions in the instrument. The details of other errors and implications for reducing key survey errors are discussed.
  Authors: Son, Sanghoon; Khattak, Asad J.; Wang, Xin; Agnello, Paul Thomas; Chen, Juyin
  Authors: Son, Sanghoon; Khattak, Asad J.; Wang, Xin; Agnello, Paul Thomas; Chen, Juyin
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 615
  Paper Number: 13-0552
  Practice-Ready: Yes
• Visualizing Transportation Improvement Plan Projects Using Three-Dimensional Virtual Globe Embedded in a Website
  Abstract: SAFETEA-LU mandates that MPOs empower the public by providing them with data and information in a format that they can easily use and understand. This includes publishing transportation plans and transportation improvement plans (TIPS) on the Internet and utilizing visualization techniques to communicate this information. This paper will describe how PPACG developed a webpage that embedded Google Earth© to display regional information showing environmental, socioeconomic and transportation layers. This includes specific instructions in using for creating the content. The goal is create an easy way for decision-makers, stakeholders and voters to understand how proposed transportation projects interact with the region.
  Authors: Casper, Craig T.; Donley, Chuck; Orwig, Paul
  Authors: Casper, Craig T.; Donley, Chuck; Orwig, Paul
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting; Society
  Session: 505
  Paper Number: 13-0575
  Practice-Ready: Yes
• Evaluation of Continuous Green T-intersections on Isolated Undersaturated Four-Lane Highways
  Abstract: The research presented in this paper analyzes the merging version of the Continuous Green T-Intersection (CGT), an alternative intersection design/control that allows certain lanes along the main street to bypass three-way intersections, with side-street traffic merging onto the main road. A comprehensive model encompassing 2,445 unique intersection condition combinations was run, comparing the merging CGT to the traditional three-way signalized intersection. The study demonstrated significant intersection improvements compared to conventional traffic signal timing. Specifically, significant benefits were observed for the merging CGT in terms of total delay, fuel usage, hydrocarbon, carbon monoxide, oxides of nitrogen, and carbon dioxide emissions. Additionally, an economic analysis showed significant user savings associated with CGT control. Because of the significantly higher volumes along the main- versus the side-street, savings for main-street vehicles outweighed any dis-benefits associated with side street traffic merging into the main street flow. These findings strongly support the decision to implement the merging CGT over traditional three-way signalized intersection control. This work introduces a comprehensive model or case study that systematically evaluates the merging CGT and compares it to conventional signalized intersection control.
  Authors: Litsas, Stephen; Rakha, Hesham
  Authors: Litsas, Stephen; Rakha, Hesham
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 405
  Paper Number: 13-0591
  Practice-Ready: Yes
• A Contemporary Model: The Culture of Progressive Longitudinal Training in the Public Transit Industry
  Abstract: Professional and workforce development is important to maintaining the safe and reliable operational integrity of the public transportation industry in the United States. This paper discusses a new concept of professional and workforce development called longitudinal training and its benefits, influences, challenges, examples, and culture. Additionally, these factors are directly associated to new advances in technology, educational techniques, paradigms, and strategies for workforce and professional development.
  Authors: Reep, Amber; Bart, Edward
  Authors: Reep, Amber; Bart, Edward
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 396
  Paper Number: 13-0589
  Practice-Ready: Yes
• Assessing National Bridge Inspection Standard Metrics Using Data Extracted from National Bridge Inventory Source Files
  Abstract: Transportation agencies face significant challenges in the maintenance, repair and operation of the nation’s bridge infrastructure as these structures continue to age and deteriorate. Compounding the issue is a chronic lack of adequate funding to perform recommended improvements, an increase in the frequency and magnitude of oversized commercial vehicles, and a dramatic reduction in the number of bridges built or reconstructed over the last decade. In response to a USDOT audit recommending the Federal Highway Administration (FHWA) develop and implement minimum requirements for data-driven, risk-based bridge oversight during FHWA annual National Bridge Inspection Standards (NBIS) compliance reviews improve, and to develop a comprehensive plan to routinely conduct systematic, data-driven analysis to identify nationwide bridge safety risks for remediation in coordination with the States, FHWA identified twenty three (23) specific metrics to assess states compliance with National Bridge Inspection Standards (NBIS) requirements and to identify potentially at-risk structures using a data driven approach. These metrics were implemented in 2011 and revised in 2012. This paper presents the results of efforts by the New Mexico Department of Transportation to refine a prototype bridge information system developed in 2010 to include a simplified means to query data contained in the National Bridge Inventory Database and to provide the means to prepare reports and randomized lists of bridges in categories related to these metrics to assist federal oversight personnel in assessing state compliance levels and recommending follow-up actions.
  Authors: Daniell, Keli T
  Authors: Daniell, Keli T
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 620
  Paper Number: 13-0636
  Practice-Ready: Yes
• Preserving an Aging Transit Fleet: Optimal Resource Allocation Perspective Based on Service Life and Constrained Budget
  Abstract: Local, county and state level transit agencies with large fleets of buses and limited budgets seek a robust fund allocation mechanism to maintain service standards. However, equitable and optimal fund allocation for purchasing, operating and maintaining a transit fleet is a complex process. In this study, we develop an optimization model for allocation of funds among different fleet improvement programs within budget constraints over the planning period. This is achieved by minimizing the Net Present Cost (NPC) of the investment within the constraint of a minimum level of fleet quality expressed as a surrogate of the remaining life of the fleet. Integer programming is used to solve the formulated optimization problem using branch and bound algorithm. The model formulation and application are demonstrated with a real world case study of transit agencies. It is observed that minimizing NPC provides a realistic way to allocate resources between different program options among different transit agencies while maintaining a desired quality level. The proposed model is generalized and can be used as a resource allocation tool for transit fleet management by any transit agency. Key Words: transit fleet, net present cost, integer programming, branch and bound algorithm
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Khasnabis, Snehamay; Mathew, Tom V.
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Khasnabis, Snehamay; Mathew, Tom V.
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Public Transportation
  Session: 352
  Paper Number: 13-0638
  Practice-Ready: Yes
• Operational and Environmental Assessment of Electric Taxi Based on Fast-Time Simulation
  Abstract: Economic pressure and increasing environmental awareness foster the development of new taxi operation technologies and procedures. One of the most promising developments is the use of electrically powered landing gears for medium-sized aircraft in civil aviation. Meeting the prerequisite that the weight of the new equipment and the weight of the saved fuel is approximately balanced, operational as well as economic and environmental benefits can be achieved. This paper describes the method how to assess these benefits by means of a fast-time simulation model and shows exemplary results for two airports.The first of these airports, Frankfurt (FRA), is one of the major European hub airports. Due to the higher share of heavy aircraft, which are assumed not to be equipped with an electrical landing gear, the relative benefit of almost 20% fuel savings is lower than at the second airport in the study, Berlin Brandenburg International (BER), the new capital airport, which is estimated to open in 2013. As the share of medium-sized aircraft is expected to be higher, relative fuel savings of more than 36% can be reached there. Besides of these economic and environmental impacts, also operational benefits can be observed as the aircraft can back out from their parking stands autonomously. By this, the time-consuming coupling and decoupling of a pushback vehicle can be saved.
  Authors: Wollenheit, Richard; Mühlhausen, Thorsten
  Authors: Wollenheit, Richard; Mühlhausen, Thorsten
  Year: 2013
  Document Type: Paper
  Subject: Aviation
  Session: 754
  Paper Number: 13-0721
  Practice-Ready: Yes
• Development of Test Method for Assessing the Bonding Characteristics of Membrane Layers in Wearing Course Laid on Orthotropic Steel Bridge Decks
  Abstract: In order to characterize adequately the adhesive bonding strength of the various membranes with surrounding materials on orthotropic steel decks and collect the necessary parameters for FE modeling, details of the Membrane Adhesion Test (MAT) have been introduced. Analytical constitutive relations of MAT device have been derived on the basis of Williams (10). Furthermore, on the basis of experimental data obtained from MAT, ranking of the bonding characteristics of various membrane products is demonstrated as well as the role of other influencing factors, such as the types of substrate and test temperatures.
  Authors: Liu, Xueyan
  Authors: Liu, Xueyan
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 335
  Paper Number: 13-0684
  Practice-Ready: Yes
• Creating a New Method to Identify the Worst Bottlenecks in Texas
  Abstract: Since 2009 the Texas Department of Transportation (TxDOT) has posted a list of the most congested roadway sections in the state on its website (1). This list is produced annually by TxDOT and the Texas Transportation Institute (TTI) using a jointly-developed methodology. The two agencies have developed an approach that combines traffic speed data from annual archives of private sector data companies, basic roadway geometry, and traffic counts published in the TxDOT statewide roadway inventory file (RHiNo) (2) to calculate congestion-related performance measures. A set of volume distribution curves, combined with daily traffic counts, is used to estimate 15-minute volumes for each average day of the week. These estimated 15-minute volumes are combined with 15-minute speed data to calculate delay. Performance measures such as annual delay per mile, congestion cost, and the Travel Time Index are produced from this analysis and are used to rank the congested segments across Texas. This paper describes the process used to produce these statistics.
  Authors: Schrank, David Lynn; Lomax, Timothy J.; Crum, Shannon
  Authors: Schrank, David Lynn; Lomax, Timothy J.; Crum, Shannon
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Policy; MAP-21
  Session: 355
  Paper Number: 13-0693
  Practice-Ready: Yes
• Hazardous Driving Event Detection and Analysis System in Vehicular Networks: Methodology and Field Implementation
  Abstract: This study proposes a novel traffic surveillance system that is capable of detecting hazardous driving maneuvers using an in-vehicle sensor and transmitting detected event data to the traffic management center (TMC) through vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication; this system is referred to as the ¡®Hazardous Driving Event Detection and Analysis System in Vehicular Networks (HEAVEN)¡¯. Compared with existing surveillance systems, the main novelty of the proposed system lies in detecting hazardous driving maneuvers that have the potential to lead to crash occurrences. Three major components of the system are introduced in this study: an algorithm for detecting hazardous driving events, a method to derive a new index representing the risk level of the traffic stream based on analyses of detected hazardous events, and field implementation of the proposed system in a testbed, using real-time and historical data. Extensive field tests have been conducted in the testbed to fine-tune the prototypical system. The methodology and field implementation presented in this study have potential value to highway traffic agencies for monitoring and evaluating traffic streams with a focus on traffic safety. The proposed system is expected to be effective in supporting the development of various traffic information control strategies for the purpose of enhancing traffic safety on highways.
  Authors: Oh, Cheol; Jeong, Eunbi; Kang, Kyeong-Pyo; Kang, Youn-soo
  Authors: Oh, Cheol; Jeong, Eunbi; Kang, Kyeong-Pyo; Kang, Youn-soo
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 668
  Paper Number: 13-0705
  Practice-Ready: Yes
• Temporal Stability of Generation Choice Models
  Abstract: This paper evaluates the temporal stability of generation choice models considering two different cases. The first case evaluates temporal stability with widely used explanatory variables and the second whether temporal stability improves with the inclusion of life cycle, area type, and accessibility. The results of this research show that generation choice models, with their ability to estimate person trips and accommodate more variables that define the traveler and the trip are temporally stable for home-based work trips by workers and home-based other trips by non-working adults. Home-based other trips by workers show mixed results with respect to temporally stability; while home-based other trips by children do not pass the test of temporal stability with any of the measures considered. This research shows that while life cycle, area type, and accessibility variables help explain travel behavior, they provide little, if any, additional benefit with respect to temporal stability.
  Authors: Huntsinger, Leta F.; Rouphail, Nagui M.
  Authors: Huntsinger, Leta F.; Rouphail, Nagui M.
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 732
  Paper Number: 13-0770
  Practice-Ready: Yes
• Tennessee Stabilized Base Using Substandard Fly Ash and Byproduct Limestone Screenings
  Abstract: Substandard fly ash (high carbon/loss-on-ignition (LOI)) and byproduct limestone screenings are plentiful materials in Tennessee. Utilization of these materials could result in both economic and environmental benefits. The Tennessee Department of Transportation (TDOT) Specification 312 for an Aggregate-Lime-Fly Ash Stabilized Base Course includes hydrated lime, fly ash, and TDOT Grading C limestone. The specification requires an average compressive strength of 950-psi (6.5-MPa) for three specimens, with no individual compressive strength less than 800-psi (5.5-MPa), after 28-days of curing at 100 °F (37.8 °C).The use of substandard fly ash and limestone screenings was compared to the use of standard materials. The control set consisted of the control fly ash with an aggregate blend, while the variable sets consisted of the control and variable fly ashes, respectively, with limestone screenings. The average compressive strength and coefficient of variation were 1,263-psi (8.71-MPa) and 5.8% for the control set, 1,416-psi (9.76-MPa) and 4.9% for the first variable set, and 966-psi (6.65-MPa) and 3.2% for the second variable set, respectively. The average static modulus of elasticity and coefficient of variation were 3,000-ksi (20.68-GPa) and 7.8% for the control set, 2,650-ksi (18.27-GPa) and 5.2% for the first variable set, and 1,400-ksi (9.65-GPa) and 8.7% for the second variable set, respectively.Analysis of these results indicates that a high LOI fly ash can be useful as a stabilizing agent when used in combination with hydrated lime. These results also suggest that byproduct limestone screenings can be used effectively as a significant part of the aggregate.
  Authors: Dillon, Sarah; Crouch, Lewis Keith; Knight, Marcus L.
  Authors: Dillon, Sarah; Crouch, Lewis Keith; Knight, Marcus L.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 694
  Paper Number: 13-0776
  Practice-Ready: Yes
• Effect of Weather and Road Surface Conditions on Traffic Speed of Rural Highways
  Abstract: This paper describes a study focusing on the impact of winter weather and road surface conditions on the average vehicle speed of rural highways with the intention of examining the feasibility of using traffic speed from traffic sensors as an indicator of the performance of winter road maintenance (WRM). Detailed data on weather, road surface conditions, and traffic over three winter seasons from two two-lane and two four-lane rural highways in Iowa, US, are used for this investigation. Three modeling techniques are applied and compared for modeling the relationship between traffic speed and various road weather and surface condition factors, including multivariate linear regression, artificial neural network (ANN), and time series analysis. The modeling results have confirmed the statistically strong relationship between traffic speed and road surface conditions, suggesting that speed could potentially be used as an indicator of bare pavement conditions and thus the performance of winter road maintenance operations. The analysis has also confirmed the expected effects of several weather variables including precipitation, visibility, temperature and wind speed. Lastly, the time series model developed could be a valuable tool for predicting real-time traffic conditions based weather forecast and planned maintenance operations.
  Authors: Cao, Luchao; Thakali, Lalita; Fu, Liping; Donaher, Garrett
  Authors: Cao, Luchao; Thakali, Lalita; Fu, Liping; Donaher, Garrett
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Safety and Human Factors
  Session: 251
  Paper Number: 13-0779
  Practice-Ready: Yes
• Benefits of Real-Time Transit Information and Impacts of Data Accuracy on Rider Experience
  Abstract: When presented in a practical format, real-time transit information can improve sustainable travel methods by enhancing the transit experience. This paper identifies the positive shift realized by the continued development of the OneBusAway set of real-time transit information tools. In addition, the paper analyzes real-time prediction errors and their effects on the rider experience. Three years after the development of location-aware mobile applications, a survey of current OneBusAway users was conducted in 2012 in order to compare the results to the previous 2009 study. The results show significant positive shifts in satisfaction with transit, perceptions of safety and ridership frequency as a result of the increased use of real-time arrival information. However, this paper also provides a perspective of the margin of error riders come to expect and the negative effects resulting from inaccuracies with the real-time data. While riders on average will ride less when they have experienced errors, a robust issue-reporting system as well as the resolution of the error can mitigate the initial negative effects. With this understanding, the paper provides transit agencies and developers with guidance to realize the full potential of real-time information and error-reporting systems.
  Authors: Gooze, Aaron; Watkins, Kari Edison; Borning, Alan
  Authors: Gooze, Aaron; Watkins, Kari Edison; Borning, Alan
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 761
  Paper Number: 13-0785
  Practice-Ready: Yes
• Continuum Approximation of Discrete Spatial Data for Optimal Facility Location Design
  Abstract: The paper proposes methodologies to convert discrete spatial data into continuous functions in a metric space so that the continuous approximation (CA) optimization framework can be applied to a general class of discrete facility location problems. We integrated a range of computational geometry methods to estimate the optimal system costs and the optimal number of facilities, and then developed an enhanced disk model to compute near optimal facility location design, both based on discrete input data. The results from the proposed CA method can be further improved by neighborhood search algorithms. Numerical experiments show that the proposed CA framework effectively finds near-optimum solutions to very large problem instances within a short time.
  Authors: Peng, Fan; Ouyang, Yanfeng; Wang, Xin
  Authors: Peng, Fan; Ouyang, Yanfeng; Wang, Xin
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 393
  Paper Number: 13-0791
  Practice-Ready: Yes
• Delays Caused by Incidents: Data-Driven Approach
  Abstract: Road networks are becoming more and more vulnerable for incidents as a result of an increasing level of congestion. In this paper an innovative empirical method is proposed and applied to analyze the delays caused by about 490.000 incidents that occurred in the Netherlands in the period 2007-2009. The method has been applied to the motorway network of the Netherlands for which detailed loop detector data is available and for which incidents are registered. The method contributes to the existing literature by explaining how delays that are caused by incidents can be computed by selecting a reference day and by tracing the effects of incidents. The method considers upstream delays on the road where the incident occurred, spillback effects to other roads and rubbernecking effects. The method provides insight in the locations that are most vulnerable for incidents and provides a basis for taking robustness measures and understanding the potential benefits of these measures.
  Authors: Snelder, Maaike; Bakri, Taoufik; van Arem, Bart
  Authors: Snelder, Maaike; Bakri, Taoufik; van Arem, Bart
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 231
  Paper Number: 13-0758
  Practice-Ready: Yes
• Public Service Assessment of Proposed Road Construction Projects
  Abstract: A public service based assessment of alternative road construction projects was designed by Bernalillo County, New Mexico, from 2006 to 2008. The purpose of the initiative was to assess and prioritize road projects for capital investment that would independently advise policy decisions. The research phase of the initiative included benchmarking national and international practice. The development phase addressed alternative ways of assessing and prioritizing completed as well as proposed road reconstruction and construction projects. Public service based assessment was successfully deployed in 2008 to advise allocation of bond revenue. Distinguishing characteristics of the public service evaluation are: 1) criteria used to indicate how well a road project would address public needs are measurement based, 2) other non-quantifiable observations are separately noted, and 3) the process involves the public and the results are transparent to the public within and across bond cycles. As of November 2012, the technical evaluation has been successfully deployed in three successive bond cycles. Public service assessment of road projects has been integrated into ongoing operations, has been extended to other types of capital improvements, and retains its technical integrity.
  Authors: Miller, Stephen Robert
  Authors: Miller, Stephen Robert
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 412
  Paper Number: 13-0759
  Practice-Ready: Yes
• Otta Seals: Surfacing Solution in Developing Regions
  Abstract: The provision and sustainability of infrastructure in the developing world remains a huge challenge for road authorities, and funding and donor agencies. Gravel roads provide early life service, but later fail in their function because of inadequate maintenance. Traditional surfacings such as chip seals or asphalt require high quality materials and specialist expertise, which may not always be available in outlying areas. A cost effective solution to providing durable surfacings is the Otta seal. It consists of a soft binder and a graded aggregate, and can be constructed labour intensively with minimal equipment. The objective of the paper is to present a case for wider use of Otta seals in countries in transition to ensure a long-lasting transport legacy. Brief detail is provided on the design and construction of the Otta seal, and the extent of international use and performance. Confirmation of the technical capabilities leads to the evaluation of the socio-economic and institutional sustainability, which are critical issues in the implementation. On the basis of the review presented, it is concluded that the Otta seal is technically feasible and economically sustainable, and thus a suitable option for surfacing that needs to be seriously considered by road authorities and donor agencies.
  Authors: Visser, Alex T.
  Authors: Visser, Alex T.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design; Pavements
  Session: 245
  Paper Number: 13-0809
  Practice-Ready: Yes
• Impacts to Transit from Variably Priced Toll Lanes: Results from U.S. Department of Transportation Urban Partnership Agreements
  Abstract: This paper describes the impacts to transit performance from three separate conversions of high occupancy vehicle (HOV) lanes into variably priced high occupancy toll (HOT) lanes in Miami, Minneapolis, and Atlanta. The data showed that the conversions had no negative impact on bus performance. In all three cities, the buses experienced travel time savings after the conversion: 17 minutes in Miami, 4.5 minutes in Minneapolis, and 5 minutes in Atlanta. Similarly, the HOT conversions did not negatively impact bus ridership. Ridership increased over the baseline by 57 percent in Miami and 13 percent in Minneapolis. In Atlanta, ridership increased by 11 percent, and this increase began prior to the conversion. The overall perception of the HOT lanes by bus riders has been positive. In surveys, the bus riders from Miami and Minneapolis gave high ratings for travel times and reliability in the HOT lane corridors. Riders in Atlanta rated the bus service as “very good” but were not as positive about the tolls. They disagreed that the HOT conversion has improved their travel or been good for the Atlanta region. These negative responses may be due in part to widespread disgruntlement with the HOT concept that existed even prior to implementation.
  Authors: Pessaro, Brian Michael; Turnbull, Katherine F.; Zimmerman, Carol A.
  Authors: Pessaro, Brian Michael; Turnbull, Katherine F.; Zimmerman, Carol A.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 775
  Paper Number: 13-0821
  Practice-Ready: Yes
• Analytical Model to Estimate Lock Capacity of a Waterway Lock
  Abstract: With the rapidly increasing traffic demand, many of locks which had promoted to develop inland waterborne transport in past decades become the major bottlenecks in the waterway system. China has promoted those locks by adding the third (even fourth) chamber in parallel to existing ones, aiming to expand the lock capacity as well as to reduce the delay. For those locks¡¯ performance, although much attention has been paid to delays with simulation models, an analytical model is also necessary to estimate the lock capacity reasonably if there is no history data to work with a simulation approach. In this paper, an improved analytical model is developed for a waterway lock based on the relationship between the area and tonnage (RAT) of inland freight vessels and the percent of available chamber (PAC). According to the observed data on the Yangtze River and Grand Canal, China, the RAT of freight vessel was analyzed using linear regression and quadratic polynomial regression, and the PAC ranges from 0.5 to 0.7. The validation shows the analytical model is reasonable. The model can estimate the lock capacity continuously with the parameters instead of the lockage arranging discretely at different level of traffic. It is useful to analyze the effect of the vessels¡¯ large and uniform trend on the lock capacity efficiently and reasonably.
  Authors: Liao, Peng
  Authors: Liao, Peng
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Marine Transportation; Planning and Forecasting
  Session: 345
  Paper Number: 13-0840
  Practice-Ready: Yes
• Factors Potentially Influencing Productivity in Performance-Based Maintenance Contracts: International Study of Roads from Sweden
  Abstract: Measuring productivity of the maintenance contractors is extremely difficult and not practical under existing scenarios. It would be more advantageous to determine what factors potentially influence productivity of the maintenance contractors, especially with Performance-Based Maintenance Contracts (PBMC). Sweden commissioned this study to determine practices in progressive countries involved in PBMC and how productivity can be influenced. The objective was to determine what factors potentially influence the productivity of the maintenance contractors and what actions can clients (agencies) consider. Additionally, it was intended to find potential solutions and investigate better practices that affect or influence productivity.The study approach consisted of a literature review and semi-structured interviews in six different countries consisting of Sweden, Finland, The Netherlands, England, Ontario, Canada, and the Virginia Departments of Transportation, in the USA. Each country responded to questionnaires concerning productivity factors.The results show that no clients included in the study measure the contractor’s productivity in PBMC. Competition for maintenance services is the primary factor to influence productivity and by using a performance based approach in a hybrid-type PBMC. Other factors identified include a more balanced risk approach, longer term agreements, bundling services, optimized service area, and using as much performance requirements as possible. The study showed that productivity of the maintenance contractor’s is complex and difficult to assess, but can be influenced indirectly by various factors. Also, there are options that practitioners can possibly adapt to help improve the productivity and efficiency by seeking solutions elsewhere.
  Authors: Pakkala, Pekka
  Authors: Pakkala, Pekka
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Maintenance and Preservation
  Session: 495
  Paper Number: 13-0844
  Practice-Ready: Yes
• A Multicriteria Approach for Analyzing Railway Service Quality
  Abstract: The objective of this work is to propose a tool for decision makers useful for verifying transit service quality and establishing the best transit service. Specifically, multiple criteria decision methods are proposed to evaluate a number of rail routes, on the basis of a set of variables describing the quality of the service, and by considering users opinions. The criteria adopted in the analysis represent some service quality attributes such as safety, cleanliness, passenger comfort, regularity and punctuality of the runs, and passenger information. We analyse the services offered by rail operators in the Northern Italy; specifically, 11 regional lines connecting the city of Milan to other towns of the hinterland are analysed. To apply the analysis, data collected in a survey conducted in June 2011 and addressed to a sample of more than 16,000 passengers are used. We obtained interesting results from the application of two different methods of multi-criteria analysis.
  Authors: Eboli, Laura; Mazzulla, Gabriella
  Authors: Eboli, Laura; Mazzulla, Gabriella
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 761
  Paper Number: 13-0853
  Practice-Ready: Yes
• Establishing Values of Time for Freight Trucks to Better Understand the Impact of Toll Policies
  Abstract: Many freight models have considered only travel time as the path building criterion, but truck drivers are sensitive to both time and cost when choosing routes. In addition, a key variable in understanding a driver’s choice when in the presence of tolls is the value of time. Research has suggested that the value of time varies considerably by the parameters of the haul, principally the type of truck and the commodity carried. Behavioral methods of ascertaining passenger values of time are limited in the variety of values of time that can be conveniently obtained, while there are a large number of commodities and truck types that can carry them. Fundamentally, truck drivers attempt to minimize costs, although they may do so imperfectly. This paper uses a policy-sensitive truck cost model to obtain values of time and tests those values of time on a full-scale simulation.A highly-detailed cost model of trucking was previously developed by our research team (1) for the purposes of policy analysis. This cost model originally followed industry practice by basing most cost components on the length of haul, which would imply that truckers would mostly minimize distance when choosing routes. However, many cost components are more logically related to the time duration of the haul. This leads to two possible hypotheses, time and distance-based costs and distance-based costs, each resulting in different values of time.The values of time were tested by simulating truck traffic in a 10-state region that included numerous toll facilities. Comparisons of the simulation results to actual traffic data from ATR stations from the State of Ohio and from counts provided by the Ohio Turnpike Authority suggest that the values of time more closely follow the time and distance-based cost hypothesis.
  Authors: Horowitz, Alan J.; Hussein, Mazen; Mei, Qinfen
  Authors: Horowitz, Alan J.; Hussein, Mazen; Mei, Qinfen
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 413
  Paper Number: 13-0865
  Practice-Ready: Yes
• Bridge Management Practices in Idaho, Michigan, and Virginia
  Abstract: Bridge management practices of departments of transportation (DOTs) in Idaho, Michigan and Virginia, are reported. These DOTs are examples of the success that is possible for asset management practices applied to bridges and culverts. Idaho, Michigan and Virginia manage their structures by: Identifying structures to be preserved; Measuring performance of structures; Setting goals for performance; Applying work programs that respond to performance measurements; Reporting performance to stakeholders, and; Leveraging State-wide commitment to preservation of assets.
  Authors: Hearn, George; Pan, Shyan-Yung; Casey, Wade F.
  Authors: Hearn, George; Pan, Shyan-Yung; Casey, Wade F.
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 602
  Paper Number: 13-0869
  Practice-Ready: Yes
• Modeling the In Situ Performance of Cement Stabilized Granular Base Layers of Urban Roads
  Abstract: This study used a three dimensional non-linear orthotropic computational road model to measure the performance of reclaimed and recycled Portland cement concrete (PCC) aggregates and reclaimed asphalt pavement (RAP) aggregates stabilized with cement, as a base layer in a City of Saskatoon local road structure. The pavement structure used in this study was a typical City of Saskatoon local road structure, composed of 45 mm hot mix asphalt concrete (HMAC) on 225 mm granular base, built directly on top of in situ subgrade. The cross section was analysed with a conventional granular base layer as a baseline, and PCC and RAP base layers with two percent cement stabilization. The cement stabilized PCC and RAP base layers showed improved shear strain and horizontal strain behaviour when compared to the conventional granular base layer (which was not cement stabilized). This improvement confirms that cement stabilization of reclaimed PCC and RAP materials provides an enhanced primary response. This study demonstrated that typical thin COS pavement structures are highly dependent on base layer material constitutive properties. Stabilizing the PCC and RAP base layers with 2% cement reduced the maximum shear strains at the edge of the pavement structure by 12% and 25%, respectively, compared to the unstabilized conventional granular base layer. It is believed the increased fracture and cohesion of the residual cementitious materials inherent to recycled granular base, as well as cementitious binder added, improved the structural performance.
  Authors: Soares, Roberto; Haichert, Rielle; Podborochynski, Diana; Berthelot, Curtis F.
  Authors: Soares, Roberto; Haichert, Rielle; Podborochynski, Diana; Berthelot, Curtis F.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 664
  Paper Number: 13-0879
  Practice-Ready: Yes
• Expanding Transportation Education Across the Academy: The Sustainable City Year Program
  Abstract: Transportation agencies are grappling with new and unfamiliar issues from addressing big problems like climate change to focusing on accessibility, where land use, urban design, and active transportation modes are more important. These challenges come at a time when the resources necessary to meet them are scarce and many agency staff members are reaching retirement. At the same time, Universities continue to attract a new generation of students who are not only comfortable and familiar with these new concepts, but are eager for a workplace that embraces this multi-disciplinary environment.A multi-disciplinary approach that includes fields not normally associated with transportation would seem to be critical to making sustainable transportation thrive in the complex environment of the city. The Sustainable City Year Program (SCYP) at the University of Oregon addresses this complexity head on by annually connecting twenty-five courses across ten or more disciplines with transportation and other sustainability projects identified by city staff of a different city each academic year. Each year, about 25 faculty and 500 students give over 80,000 hours of effort to help local cities move forward on vexing issues. Students gain professional hands-on experience, an opportunity to learn from multiple disciplines, and an understanding that complex transportation issues require a diverse set of skill sets and perspectives to solve. This paper describes SCYP, highlights a few transportation-specific projects that “non-traditional” transportation students take on, and presents a new model for higher education across the country that can help train the next generation transportation workforce.
  Authors: Schlossberg, Marc A.; Larco, Nico
  Authors: Schlossberg, Marc A.; Larco, Nico
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 504
  Paper Number: 13-0862
  Practice-Ready: Yes
• Model for Light-Rail Transit Operation and Maintenance Cost to Perform Sensitivity Analysis
  Abstract: A Light Rail Transit (LRT) Operation and Maintenance (O & M) cost model was developed using various system attributes namely Route Miles, Train Revenue-Hours, Car Revenue-Miles and Peak LRT Cars. System attributes and cost data of twelve peer LRT facilities from 2004-2008 were collected in this context. Using a regression technique, five sets of Power Factor Models (PFM) representing Total O & M cost, Vehicle operation cost, Vehicle maintenance cost, Non-vehicle cost and Administrative cost were derived. The Total O & M cost computed by PFM as well as by the weighted Fully Allocated Cost (FAC) method were compared. It was observed that Total O & M cost computed using PFM is closer to the actual cost. Distribution of predicted Vehicle operating cost, Vehicle maintenance cost, Non-vehicle cost and Administrative cost closely matched the observed distribution. Also, as a part of this study, a set of computation tools (three Nomo-graphs and utility cost calculator) were established to serve as a quick response instrument to estimate Total O & M cost, Vehicle operation cost and Non-vehicle maintenance cost as well as to perform sensitivity analysis.
  Authors: Dutta, Utpal; Zhong, Xiaohui
  Authors: Dutta, Utpal; Zhong, Xiaohui
  Year: 2013
  Document Type: Paper
  Subject: Public Transportation
  Session: 794
  Paper Number: 13-0888
  Practice-Ready: Yes
• Simulating High-Occupancy-Toll Lane Operations
  Abstract: Microscopic simulation is critical for evaluating the operation strategies of managed lanes. However, most existing tools are limited in their ability to simulate dynamic tolling strategies of managed lanes, particularly with multiple segments. Three sets of modeling components are developed in this paper, to demonstrate simulation of HOT lane operations. The first component implements three pricing strategies; including responsive pricing, a closed-loop-control-based algorithm, and time-of-day pricing. The second component mimics drivers’ lane choice behaviors in the presence of tolls, and the third represents different toll structures for multi-segment HOT lane facilities. An enhanced version of CORSIM, which contains these new modeling components, is validated by simulation experiments involving the 95 Express network in South Florida.
  Authors: Michalaka, Dimitra; Yin, Yafeng; Hale, David
  Authors: Michalaka, Dimitra; Yin, Yafeng; Hale, David
  Year: 2013
  Document Type: Paper
  Subject: Finance; Operations and Traffic Management; Policy
  Session: 294
  Paper Number: 13-0890
  Practice-Ready: Yes
• Police Enforcement Strategies and Speed Reduction in Work Zones
  Abstract: Highway work zone safety is a nationwide concern and it will likely draw ever increasing attention as the number of highways that require renovation or maintenance increases. In an effort to improve work zone safety now and in the future, the Indiana Department of Transportation (INDOT) recently established a special fund for work zone speed enforcement and further commissioned the authors of this study to help them achieve the maximum safety benefits within their budget constraint. A previous study by the authors modeled the crash frequency in Indiana work zones with various features, which provided the potential for safety improvement. In this study, the focus is on evaluating the effectiveness of police enforcement strategies in reducing driving speed in work zones. These results will be eventually included in a comprehensive method for optimizing enforcement strategies and resource allocation to improve work zone safety. Different combinations of stationary police enforcement, with or without supplemental variable message signs (VMS), were evaluated in six work zone sites. The authors conducted data collection using experiment design techniques and multilevel linear modeling for the data analysis with the goal of finding the best way to estimate the effectiveness of enforcement strategies. The developed statistical model allows predicting speed reduction as a function of police enforcement elements and roadway characteristics. The results indicate that spreading enforcement resources among multiple work zones is a good strategy instead of concentrating enforcement on a smaller number of work zones. Furthermore, adding VMS with relevant messages about enforcement greatly increases the effectiveness of the enforcement program.
  Authors: Chen, Erdong; Tarko, Andrew P.
  Authors: Chen, Erdong; Tarko, Andrew P.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0927
  Practice-Ready: Yes
• Probability Analysis of Damage to Offshore Pipeline by Ship Factors
  Abstract: The transport of hydrocarbons by offshore pipeline is threatened by the rapid expansion of pipe networks and the increasing frequency of maritime activities. Risk management is thus necessary to manage and prevent ship-related hazardous events that may damage offshore pipelines. Probability analysis is the key to assessing the risk associated with ship operations on offshore pipelines, and decision making in managing that risk. Bayesian Network (BN) models are proposed in this paper to determine the probability of anchor damage and trawling damage to subsea pipelines. The BN models are developed by integrating directed acyclic graphs, and three computational methods (Boolean operation, standard and historical statistical analysis, and fuzzy set theory) to elicit marginal probability tables and conditional probability tables. A case study illustrates the utilization of two BN-related functions ¨C probability prediction and probability updating ¨C to determine final probabilities of damage to a subsea pipeline. The results of the analysis support risk ranking and risk reducing decisions associated with maritime operations in the area of offshore pipelines.
  Authors: Liu, Yutao; Hu, Hao; Zhang, Di
  Authors: Liu, Yutao; Hu, Hao; Zhang, Di
  Year: 2013
  Document Type: Paper
  Subject: Marine Transportation; Pipelines; Safety and Human Factors
  Session: 637
  Paper Number: 13-0923
  Practice-Ready: Yes
• Simplified Analytical Approach to Predict Temperature Profile Within Portland Cement Concrete Slab During FWD Testing
  Abstract: Temperature profile in the Portland cement concrete slab of a rigid pavement plays an important role in analyzing and interpreting Falling Weight Deflectometer (FWD) testing data. This paper presents a simple analytical method to rapidly predicting time-dependent temperature profile in the concrete slab based on measured rigid pavement surface temperature data during FWD testing. In this paper, the classical solution of one-dimensional heat equation for a homogeneous half-space subjected to specified surface temperature data is employed; and an efficient Gaussian-quadrature numerical scheme to approximating the improper integrals in the classical solution is identified. The cubic spline interpolation technique is used to generate surface temperature history based on measured surface temperature data at different times during FWD testing.Based on the FWD temperature data collected in the well-known Long-Term Pavement Performance Program, total 2,215 subsurface temperatures within concrete slabs were predicted for different climatic regions. Comparisons between predicted and measured subsurface temperatures suggested that the proposed simple analytical method yielded reasonable temperature profile within concrete slabs in rigid pavements.
  Authors: Wang, Dong
  Authors: Wang, Dong
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 554
  Paper Number: 13-0933
  Practice-Ready: Yes
• Approach to Optimization of Winter Road Management Operation by Taxi Probe Data
  Abstract: Traffic smoothness must be ensured through winter road management. The average travel speed is a key of indicator that represents traffic smoothness. In this study, we used taxi probe data to obtain average travel speeds in the Sapporo urban area, Japan for a long period of time, and analyzed the relationship between the average travel speed and various winter weather and road surface conditions. Also, we calculated the monetary value of the increase in average travel speed afforded by snow and ice control operations. We had been acquired taxi probe data 6 months from October 1st, 2010 to March 31st, 2011, with the cooperation of a taxi company. Differences in average travel speed between the winter season and the non-winter season have been found to vary depending on weather and road surface conditions. Our survey has found that snow and ice control operations increase the average travel speed of road users. Improved average travel speed increases the benefits for road users. The cost-benefit analysis of snow and ice control operations for national highways in Sapporo found that the estimated benefits of winter road management operations far exceeded the cost of such work operations. This paper proposes an approach to a balance and optimization of winter road management and winter service using the taxi probe data.
  Authors: Munehiro, Kazunori; Kageyama, Hiroyuki; Takahashi, Naoto; Ishida, Tateki; Asano, Motoki
  Authors: Munehiro, Kazunori; Kageyama, Hiroyuki; Takahashi, Naoto; Ishida, Tateki; Asano, Motoki
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Safety and Human Factors
  Session: 251
  Paper Number: 13-0952
  Practice-Ready: Yes
• Investigation of Lane Flow Distribution on Hard Shoulder Running Freeways
  Abstract: Responding to an impending demand growth at an existing reactive managed lane system, and in order to provide a timely and more effective temporary hard shoulder activation, short-term prediction models are developed. A lane-oriented attribute, namely the left lane flow distribution ratio (LLFDR), is introduced, aiming to ameliorate the system by capturing the forthcoming stream dynamics and reconfiguring it to proactive. To assess the impact of its implementation to the network's performance, an exploratory analysis was effectuated based on data acquired by seven radar sensors located every 500 m, along a Swiss freeway section that is not affected from incoming or exiting traffic. A locally weighted regression is employed to provide a more accurate insight of the traffic behaviour, comparing observations derived during the regular operation of the system and a period that it was suspended, with respect to seasonality patterns. To describe the impending stream motion by examining different time-volume clusters (off-peak and rush-hour), two prediction models were specified according to the time range. The preliminary results of the study for several prediction horizons, demonstrate an acceptable prediction uncertainty. The hard shoulder activation prediction confirms the analysis of the operation impact findings of this research.
  Authors: Samoili, Sofia; Efthymiou, Dimitrios; Antoniou, Constantinos; Dumont, Andre-Gilles
  Authors: Samoili, Sofia; Efthymiou, Dimitrios; Antoniou, Constantinos; Dumont, Andre-Gilles
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: 13-0964
  Practice-Ready: Yes
• Safety Evaluation of Discontinuing Late Night Flash Operations at Signalized Intersections
  Abstract: This study examined the safety impacts of converting late nighttime flash (LNF) to normal phasing operation at signalized intersections by means of the empirical Bayes (EB) before-after method, and the univariate and multivariate Full Bayesian (FB) before-after methods. Data were obtained from the North Carolina Department of Transportation and included 61 treatment sites and 395 reference intersections that remained on LNF operation from 2000 to 2007. The results from the EB method are almost identical to those of the univariate FB. The FB method offered more flexibility in selecting the functional form of expected crashes at similar sites (similar to the SPF in the EB), and addressing uncertainty in the data. Compared to the univariate FB, the multivariate FB using the multivariate poisson lognormal model (MVPLN) provided better results based on much lower deviance information criterion (DIC) values. The MVPLN model was favored and the recommended CRFs are 48% (±6%), 53% (±8%), and 57% (±7%) for night, injury and fatal, and frontal impact crashes, respectively.
  Authors: Lan, Bo; Srinivasan, Raghavan
  Authors: Lan, Bo; Srinivasan, Raghavan
  Year: 2013
  Document Type: Paper
  Subject: Safety and Human Factors
  Session: 289
  Paper Number: 13-0988
  Practice-Ready: Yes
• Operational Analysis of Freeway Variable Speed Limit System: Case Study of Deployment in Missouri
  Abstract: Variable Speed Limit (VSL) systems have been more widely implemented in Europe as compared to the United States. Studies have demonstrated positive safety impacts of such systems; however, there are very few studies that used actual deployment data to investigate the operational benefits of VSL systems. This paper presents the operational impacts of a VSL deployment on Interstate 270 in the state of Missouri in United States. Techniques such as parametric curve fitting, non-parametric methods, and other statistical tests were used to identify the traffic changes between before and after conditions. The effect of VSL on traffic performance was investigated at eight heavily congested locations. The two-dimensional Kolmogorov-Smirnov test results indicated that flow-occupancy diagram changes were statistically significant at seven out of eight locations. The slopes of flow-occupancy plots for over critical occupancies were found to be steeper after VSL. Slight changes in critical occupancy were observed after VSL implementation. However, the changes were inconsistent across locations with some witnessing an increase and others witnessing a decrease. The maximum flow prior to breakdown, the pre-breakdown flow, decreased at four locations and increased at four locations after VSL. The maximum flow after breakdown, the post-breakdown flow, decreased at three locations and increased at five locations after VSL. The average daily duration of congestion decreased at five locations and increased at three locations after VSL. Findings of this study help to develop VSL control algorithms that are more efficient in improving VSL traffic operations benefits.
  Authors: Kianfar, Jalil; Edara, Praveen; Sun, Carlos
  Authors: Kianfar, Jalil; Edara, Praveen; Sun, Carlos
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 778
  Paper Number: 13-0986
  Practice-Ready: Yes
• Understanding Public Involvement Practice in North Carolina Metropolitan Planning Organizations: Analysis of Goals and Tactics
  Abstract: Transportation planning in the United States is conducted by a range of federal, state and local agencies, each with its own interests and constituencies. Metropolitan planning organizations (MPOs) have emerged as one of the dominant forces in shaping the future of America’s major highways and transit systems. As a part of their federally-mandated duties for planning for major transportation infrastructure, MPOs have been charged with involving the public in their decision making. Though certain state and federal public participation requirements apply to all 17 of North Carolina’s MPOs, there are differences in the ways that these organizations engage with those requirements and provide or do not provide meaningful opportunities for public involvement in the planning that they do. This paper explores and records those differences. Through a comparison of the tactics that MPOs used in their public involvement programs and the goals that MPOs set for those programs, this paper outlines several strengths and weaknesses of current practice.Major strengths of current practice include a diversity of tactics and opportunities for involvement throughout the process. A prevalence of tactics that are more informational in nature, a lack of online participation methods, and inadequate attention on underserved groups are some of the key weaknesses. These strengths and weaknesses suggest four key recommendations for moving forward. MPOs should pay more attention to underserved groups, seek to get feedback from residents (as opposed to educating them), move some participation online and move beyond simply meeting federal requirements.
  Authors: Miles, Jeffrey David
  Authors: Miles, Jeffrey David
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting; Society
  Session: 505
  Paper Number: 13-1069
  Practice-Ready: Yes
• Evaluation of Possible Directions for Improving Traffic Management Systems
  Abstract: Traffic Management System (TMS) is one of the most effective tools to control congestion in urban areas as it aims to eliminate congestion through application of advanced technologies. As a result of evolving socioeconomic status of the urban areas, the demand for mobility and transportation is increasing. Likewise, traffic management needs are shifting to new directions to meet emerging mobility needs. Advancements in traffic detection, information technology and computing efficiency offer great potentials for improving the functionality of Traffic Management System. However, identification of the potential directions for improvements requires revisiting the needs for traffic management, evaluation of the existing deployments and envisioning the future needs. This article is an effort to evaluate the emerging needs and possible improvements for Traffic Management System. Examples of the Traffic Management System deployments in Asia, Europe and North America were reviewed and compared in terms of the system provider, input data requirements, ITS technologies and system outputs. Major issues and challenges of existing practices were investigated and emerging traffic management needs for various system users were highlighted from the view point of traffic operations and planning. Feasibility of implementing new technologies in Traffic Management System was evaluated and possible directions for improvements were discussed.
  Authors: Mehran, Babak
  Authors: Mehran, Babak
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 668
  Paper Number: 13-1073
  Practice-Ready: Yes
• Effects of High-Visibility Enforcement on Driver Compliance to Pedestrian Yield Right-of-Way Laws
  Abstract: This study examined the effects of a one-year high visibility pedestrian right-of-way enforcement program on yielding to pedestrians at uncontrolled crosswalks, some of which received enforcement and some of which that did not. The program included four 2-week enforcement waves, supported by education and engineering components that increased the visibility of enforcement. The study produced five results. 1. Enforcement led to a slow and steady increase in the percentage of drivers yielding right-of-way to pedestrians over the year. 2. The program produced a large change in yielding over the course of the year. 3. The program produced higher levels of yielding to natural pedestrian crossings than to staged crossing and the changes in both were highly correlated. 4.The effects of the program generalized to crosswalks that were not targeted for pedestrian right-of-way enforcement. 5.The amount of generalization to unenforced sites was inversely proportional to the distance from sites that received enforcement.
  Authors: Van Houten, Ronald G.; Malenfant, J.E. Louis; Huitema, Brad; Blomberg, Richard D.
  Authors: Van Houten, Ronald G.; Malenfant, J.E. Louis; Huitema, Brad; Blomberg, Richard D.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Pedestrians and Bicyclists; Deploying Transportation Research-Doing Things Smarter, Better, Faster
  Session: 700
  Paper Number: 13-1077
  Practice-Ready: Yes
• Evaluation of Drilled Shafts with Self-consolidating Concrete
  Abstract: In this study, drilled shafts with self-consolidating concrete (SCC) were prepared and tested using cross-hole sonic logging (CSL). SCC has very high workability. It was placed in the drilled shafts of the bridge on Route 28 over Broad Run in Bristow in Prince William County, Virginia. During placement, properties of the fresh concrete were tested and specimens were prepared to determine the hardened properties. The integrity of the bridge shafts within the reinforcing cage was determined using CSL. Another sonic method, the sonic echo/impulse response (SE/IR) was used to evaluate several test shafts. Also, the use of acousto-ultrasonic (AU) measurements to determine the cover depth outside the reinforcing cage was evaluated during laboratory testing. The results indicated that SCC is highly desirable for drilled shafts; it flows easily, filling the hole, and the removal of the temporary casing is facilitated by this highly workable material. CSL is a satisfactory nondestructive method to determine the integrity of shafts. SE/IR also showed promise as a method that complements CSL for determining the integrity of a shaft. AU test was promising in the laboratory, but needs further development for implementation in the field.
  Authors: Ozyildirim, Celik; Sharp, Stephen R.
  Authors: Ozyildirim, Celik; Sharp, Stephen R.
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-1086
  Practice-Ready: Yes
• Workforce Excellence Program: Comprehensive Workforce Planning Model for Transportation Agencies
  Abstract: Strategic recruitment of vital positions, retention of highly skilled and motivated employees, and effective training and development rank foremost in the Alaska Department of Transportation and Public Facilities’ (DOT&PF) commitment to workforce planning. Transportation challenges include:•Alaska Marine Highway connects 33 coastal communities via 3,500 waterway miles•Aviation operations include two international airports and 252 rural airports – approximately 82% of communities are not served by roads•Diverse and extreme geologic and climate conditionsThe Workforce Excellence Program incorporates workforce data with an annual environmental scan to forecast future transportation workforce needs. Program focus:•2011 – training and development•2012 – recruitment and retention•2013 – knowledge transfer and career awarenessRecent DOT&PF training and development successes include:•Construction Management Graduate Certificate through University of Alaska and the Alaska University Transportation Center focusing on leadership and project management skills – credits can be applied to Master’s Degree•American Association of Airport Executives Certified Member program (AAAE CM) – professional airport management credential•Standards of Training Certification and Watchkeeping for Seafarers (STCW) training – international qualification standards for masters, officers and watch personnel•Online Supervisor ToolkitOver the next 12 months, DOT&PF will implement a Mentorship program and the Leadership Development Program. Additional online resources and tools will also be made available to department employees.Workforce Excellence strives to identify and implement workforce development best practices in the transportation industry.
  Authors: Holland, Amanda
  Authors: Holland, Amanda
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 396
  Paper Number: 13-1088
  Practice-Ready: Yes
• Snowball Effect and Traffic Equilibrium in a Market Entry Game: Laboratory Experiment
  Abstract: The Market Entry Game (Selten \& Guth, 1982 ; Gary-Bobo, 1990) is a coordination game where average cost of entry increase linearly. Following the suggestion of Anderson et al. (2008) and empirical evidence in transport economics suggested by related literature about the Speed-Flow Relationship (Verhoef, 2005), we built a theoretical model of market entry game where average entry cost grows at an increasing rate when the flow of entrants rises (snowball MEG). The calibration of experimental parameters enables us to compare outcomes regarding Snowball MEG to a benchmark based on a usual linear MEG, its experimental calibration being based on Anderson et al., 2008). Then, we run an experiment where theoretical predictions for both models give comparable aggregate entry rate and exhibit common properties. Moreover, we conduct variation about group size in order to assess size effect on coordination level. Basically, we find no significant difference between the aggregated entry rates in our snowball game compared to usual MEG. But size clearly matters, especially for issue regarding successful coordination for users in the snowball MEG.
  Authors: Denant-Boemont, Laurent; Fortat, Vivien
  Authors: Denant-Boemont, Laurent; Fortat, Vivien
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 688
  Paper Number: 13-1103
  Practice-Ready: Yes
• Development of National Pedestrian Crossing Control Guide
  Abstract: In 2010 the Transportation Association of Canada began the two-year process of updating the 1998 Pedestrian Crossing Control Manual. The resulting document, the Pedestrian Crossing Control Guide, is expected to promote uniformity across the country with respect to the approach used in the provision of pedestrian crossing control. This is done through the development of a decision support tool to assist in the decision-making process when establishing the need for pedestrian crossing control; and identifying the type of crossing control to use for the location’s characteristics. This paper discusses the design and development of the new Pedestrian Crossing Control Guide for Canada, and presents findings of the research that led to its development. The findings fall into two areas: (1) existing Canadian and international pedestrian crossing control practices; and (2) safety performance of different pedestrian crossing control devices.Principal conclusions from this research are: (1) international practice is changing towards providing “guidance” rather than formal, numerical warranting procedures in the decision making-process for pedestrian crossing control provision; (2) there are pedestrian crossing control treatments for which there is no available literature regarding their safety performance, while available literature for others lacks rigorous safety evaluations; and (3) further research is needed regarding the safety performance of pedestrian crossing control devices, particularly in the areas of understanding pedestrian collisions and developing accident prediction models.
  Authors: Montufar, Jeannette
  Authors: Montufar, Jeannette
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 459
  Paper Number: 13-1119
  Practice-Ready: Yes
• Tabu Search Heuristics for Inventory Routing Problem with Route Duration Limits and Stochastic Inventory Capacity Constraints
  Abstract: This paper studies the inventory management and routing problem in a two-level supply chain where a single plant serves a set of warehouses, which in turn serve a set of customers with stochastic demands. A set partitioning based probabilistic chance constrained nonlinear integer programming formulation is provided for the combined continuous inventory control and multi-depot vehicle routing problem while accounting for probability of inventory capacity violation, order quantity capacity, service levels, vehicle capacity restrictions and route duration limits. Two tabu search heuristics, differing in the way initial solutions are generated, are applied to solve the problem. Computational tests on standard tests networks reveal that integrating the inventory management and routing decisions by solving the combined inventory management and routing problem may yield cost savings of up to 14% over the sequential approach where both problems are solved separately. The best objective function value obtained by the tabu search heuristic was found to increase with increase in customer demand variance but decrease with increase in order quantity capacity and route duration limit. The safety stock levels, the reorder points and total holding costs were found to increase with increase in customer demand variance. The available inventory capacity was found to decrease with increase in customer demand variance. The total ordering costs in the best solution increases with the decrease of the order quantity capacity, whereas the total holding costs decreases with the decrease of the order quantity capacity. The routing costs increases with the decrease of route duration limit.
  Authors: Karoonsoontawong, Ampol; Unnikrishnan, Avinash
  Authors: Karoonsoontawong, Ampol; Unnikrishnan, Avinash
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Operations and Traffic Management; Terminals and Facilities
  Session: 248
  Paper Number: 13-1175
  Practice-Ready: Yes
• Quantifying Effects of Land Use and Socioeconomics on Generation of Traffic Emissions and Individual Exposure to Air Pollution
  Abstract: This paper presents a modeling framework developed for the City of Montreal, Canada, and is intended to quantify two indicators that can explain the spatial distribution of traffic-related air pollution at a metropolitan level. The indicators are estimated at the level of the traffic analysis zone (TAZ) and include: (1) the average level of emissions generated per individual, and (2) the level of emissions occurring in a zone as a proxy for air pollution exposure. A regional traffic assignment model is extended with capabilities for emission modeling at an individual trip level while taking into account vehicle (type, age) and trip attributes (road type, speed, volume). We observe that individuals who generate higher emissions from travel tend to reside in areas with lower exposure to traffic emissions while individuals associated with low levels of travel emissions (e.g. travel smaller distances, conduct less trips, use alternative modes) reside in areas with high levels of traffic pollution. A regression analysis of the two indicators against a set of land-use and socio-economic variables shows that generated emissions per individual are positively associated with car ownership and larger vehicles, while being negatively associated with ownership of newer vehicles, and location in dense and walkable neighborhoods with high levels of commercial land-use. Meanwhile, exposure to emissions is positively associated with dense and walkable neighborhoods and negatively associated with car ownership and larger vehicles. These findings indicate major inequities in the generation of and exposure to traffic-related air pollution.
  Authors: Sider, Timothy M.N.; Alam, Ahsan; Zukari, Muhammad; Dugum, Hussam; Goldstein, Nathan; Eluru, Naveen; Hatzopoulou, Marianne
  Authors: Sider, Timothy M.N.; Alam, Ahsan; Zukari, Muhammad; Dugum, Hussam; Goldstein, Nathan; Eluru, Naveen; Hatzopoulou, Marianne
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-1184
  Practice-Ready: Yes
• Optimization Model for Inventory Routing Problem with Third-Party Logistics Provider Consideration
  Abstract: In this research, the inventory control and transportation of syrup concentrate and final products for one bottling company working for a beverage company is studied. Bottling companies get syrup concentrate from a beverage company to mix it with different ingredients to produce various products and distribute them to retailers. Unsatisfied orders have several harmful effects on the bottling company. The main reason for not serving one retailer is that the number of vehicles is not sufficient for delivery to all retailers. One method for preventing missed orders is sending orders to some retailers in advance to hold for future use. Another way to deal with this problem is by renting vehicles, which increases the fleet size. The last is outsourcing shipping and/or warehousing. This problem belongs to Inventory Routing Problem (IRP) with some new features such as options for rental vehicle and Third Party Logistics Providers (TPLP). The proposed model in this study includes several time steps in which a decision in one time step can affect future time steps. The proposed model is a multi-tier, multi-plant, multi-warehouse, and multi-product model which considers non-homogeneous fleet. No model in the literature considers all of these characteristics simultaneously.
  Authors: Sadrsadat, Hadi; Haghani, Ali; Sharifi, Elham
  Authors: Sadrsadat, Hadi; Haghani, Ali; Sharifi, Elham
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 393
  Paper Number: 13-1193
  Practice-Ready: Yes
• Evaluation of Safety-Effectiveness of "Vehicle Entering When Flashing" Signs and Actuated Flashers at 74 Stop-Controlled Intersections in North Carolina
  Abstract: The purpose of this project is to evaluate the safety effectiveness of “Vehicle Entering When Flashing” (VEWF) intersection conflict warning systems at stop-controlled intersections. North Carolina Department of Transportation (NCDOT) has utilized this treatment consisting of vehicle actuated sign and flasher assemblies placed at or near the intersection to warn motorists on the major and/or minor road of vehicles entering the intersection. Although this countermeasure has been used for years in North Carolina, and similar intersection conflict warning system have been used in other States, there has been minimal safety evaluation to prove or validate its effectiveness. Four categories of VEWF systems are evaluated. Sites are categorized based on the direction of the alert and placement from the intersection. Crash modification factors (CMFs) are provided for all sites and each category, as well as exclusively for sites with two-lane at two-lane intersection configurations. Empirical Bayes before and after techniques were utilized to overcome the regression to the mean threat. Deployments with major road alerts in advance of the intersection and a combination of both major and minor road alerts were determined to be most effective for two-lane at two-lane stop controlled intersections with CMFs for total crashes of 0.68 and 0.75, respectively.
  Authors: Simpson, Carrie Louise; Troy, Shawn
  Authors: Simpson, Carrie Louise; Troy, Shawn
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 429
  Paper Number: 13-1159
  Practice-Ready: Yes
• Identifying Resiliency Performance Measures for Mega-Regional Planning: Case Study of BosWash Transportation Corridor
  Abstract: Transportation corridors in megaregions present a unique challenge for planners due to the high concentrations of development, the complex interjurisdictional issues and the history of independent development of the core urban centers. The concept of resilience, as applied to megaregions, can be used to better understand the peformance of these corridors. Resiliency is the “ability to recover from or adjust easily to change”. Resiliency performance measures can be expanded on for application to megaregions throughout the United States. When applied to transportation corridors in megaregions, and represented by performance measures such as redundancy, continuity, connectivity, and travel time reliability, the concept of resiliency captures the spatial and temporal relationships among the attributes of a corridor, network, and neighboring facilities over time, at both the regional and local level. This paper focuses on the development of performance measurements to evaluate corridor resiliency as well as a plan for implementing analysis methods at the jursidictional level. The BosWash corridor is used as a case study in order to represent the applicability of these measures to megaregions throughout the country.
  Authors: Oswald, Michelle Renee; McNeil, Sue; Ames, David; Gayley, Rebekah
  Authors: Oswald, Michelle Renee; McNeil, Sue; Ames, David; Gayley, Rebekah
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 418
  Paper Number: 13-1198
  Practice-Ready: Yes
• Light-Rail Transit Experience in Madrid, Spain: Effects on Population Settlement and Land Use
  Abstract: Development of new transport systems often leads to demographic and socioeconomic changes in the implementation area. However, the extent and type of these impacts varies depending on the existing settlement patterns, socio-economic conditions and project objectives. To help better understand these impacts this paper examines the effects of building two new light rail lines in Madrid. The two lines were planned to serve different functions and their service areas have different land use characteristics. LRT Line 1 was designed to help promote urban development in a lightly settled area while Line 2 was designed to encourage public transport in an already developed area. As expected, the analysis shows that the impacts of these two lines have been very different. Along Line 1 a large amount of new development has taken place and there have been large increases in population, while along Line 2 land use and population are largely unchanged. This result demonstrates the critical importance of integrated transport and land use planning in the development of cities.
  Authors: Calvo, Francisco; de Ona, Juan; Aran, Fernando; Nash, Andrew
  Authors: Calvo, Francisco; de Ona, Juan; Aran, Fernando; Nash, Andrew
  Year: 2013
  Document Type: Paper
  Subject: Public Transportation
  Session: 328
  Paper Number: 13-1162
  Practice-Ready: Yes
• Algorithms for One-to-One Time-Dependent Shortest Pathon Real Networks
  Abstract: In this research, we propose one-to-one time dependent shortest path(TDSP) algorithms, where the link flow speeds depend on time intervals. For this work, first three general shortest path algorithms which have proven to be fast and efficient algorithms in real networks are selected. These are Dijkstra¡¯s algorithm with approximate buckets, Dijkstra¡¯s algorithm with double buckets and Graph growth algorithm with two queues, and all three algorithms are to compute shortest paths from one node to all nodes in a network. These algorithms are extended to compute a shortest path from an origin node to a destination node in time dependent networks. Also, instead of travel time models, flow speed models and arrival time functions are used in the three algorithms to hold the First-In First-Out property.Three extended algorithms are tested and evaluated on 3 data sets from real networks. Data set 1 consists of 10 low-detail state road networks and data set 2 consists of 10 high-detail state road networks in the United States. Data set 3 consists of 4 urban street networks for Anaheim, CA, Baltimore, MD, Chicago, IL, and Philadelphia, PA. Based on the computational results, among the three algorithms for TDSP, the best performing algorithms for solving one-to-one time dependent shortest path for urban street networks and for state wide networks, are extended Dijkstra¡¯s algorithm with double buckets and extended Graph growth algorithm with two queues, respectively.
  Authors: Kim, Taehyeong; Haghani, Ali; Kim, Hyoungsoo
  Authors: Kim, Taehyeong; Haghani, Ali; Kim, Hyoungsoo
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 844
  Paper Number: 13-1169
  Practice-Ready: Yes
• Guidelines for Selection and Use of Recycled Concrete Aggregates in Structural Concrete
  Abstract: This paper presents guidelines for using RCA as a full or partial replacement for natural coarse aggregate in new concrete (RCA concrete). Several international standards and guidelines for the use of RCA in concrete are reviewed and contrasted to identify areas where further development is required. The main results of an extensive experimental research program by the Authors are summarized herein to provide the basis for the development of a framework for using RCA in structural concrete. Several RCA performance classes are proposed each with a specific set of requirements and suitable applications. The proposed performance classes define further requirements and guidance for the use of RCA beyond the requirements of CSA A23.1 and ASTM C33. A detailed decision tree is proposed that allows engineers, concrete producers, aggregate suppliers and contractors to assess whether a particular RCA source is suitable for use in reinforced concrete, plain concrete or as a fill material.
  Authors: Butler, Liam J; Tighe, Susan Louise; West, Jeffrey S
  Authors: Butler, Liam J; Tighe, Susan Louise; West, Jeffrey S
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 284
  Paper Number: 13-1173
  Practice-Ready: Yes
• Evaluating Laboratory Compaction Techniques of Reclaimed Asphalt Pavement
  Abstract: Reclaimed Asphalt Pavement (RAP) is a byproduct of roadway resurfacing. A limited amount can be recycled into new hot mix asphalt; the rest is stockpiled. Some states allow the use of RAP/aggregate blends as base course material. Due to its low strength and susceptibility to creep deformation the Florida Department of Transportation (FDOT) excludes RAP as pavement base course for high traffic areas. The research objective was to determine whether the strength characteristics of RAP could be improved through compaction to make it base suitable in high traffic areas. Modified Proctor, vibratory, and gyratory compaction data was compared. Four RAP sources were used. Specimens compacted by the three methods were tested using Limerock Bearing Ratio (LBR), Unconfined Compressive, and Indirect Split Tensile strength. LBR is Florida’s variation of the California Bearing Ratio. Specimens were compacted to either a density or to a compaction energy level. Vibratory compaction produced the lowest densities and strengths. Modified Proctor produced higher densities and strengths than vibratory but the LBR strengths for all RAP types were consistently below FDOT standards. Gyratory compaction produced the highest densities and strengths. Gyratory specimens of RAP were two to four times stronger than modified Proctor specimens at the same density. Compaction method did not have as significant an effect on creep, although gyratory compacted samples did produce less creep than modified Proctor compacted samples.
  Authors: Cosentino, Paul J.; Bleakley, Albert M.; Perersen, Andrew James; Sajjadi, Amir Mohammad
  Authors: Cosentino, Paul J.; Bleakley, Albert M.; Perersen, Andrew James; Sajjadi, Amir Mohammad
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1220
  Practice-Ready: Yes
• Assigning User Class Link Flows Uniquely
  Abstract: The standard method for predicting traffic flows on urban road networks, static user-equilibrium traffic assignment, is based on the principle that drivers seek their own least cost routes from their origins to their destinations. This principle corresponds to a user-equilibrium state in which all used routes have equal costs and no unused route has a lower cost for every origin-destination pair. This problem can be formulated as a convex optimization problem with linear constraints, and solved with an iterative algorithm. Although the total flows on links of the urban road network are uniquely determined by this formulation, multi-class link flows, as well as route flows, are not. An additional assumption, called the condition of proportionality, may be imposed to determine these flows uniquely. This condition was the basis for incorporating a post-processing adjustment into two commercial travel forecasting software systems, TransCAD and Visum, as well as designing a new algorithm called TAPAS. Analyses of class link flows from Visum assignments of cars and trucks to the Chicago regional network, with and without the condition of proportionality, are presented. Differences in class link flows with and without the condition of proportionality are analyzed in relation to link attributes. The findings offer insights into the importance of the condition of proportionality in multi-class road traffic assignments at the link level.
  Authors: Xie, Jun; Boyce, David
  Authors: Xie, Jun; Boyce, David
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 451
  Paper Number: 13-1215
  Practice-Ready: Yes
• Insertion Rate Model for Pile Installation by Jetting in Sand
  Abstract: The use of jetting is an approach that is used to aid the installation of the piles especially in areas encompassing hard but relatively shallow subsurface soil layers. Employing pile jetting for a part of the depth installation minimizes pile exposure to excess stresses as well as energy savings and noise reduction. There is however a dearth of information in literature regarding the appropriate selection of jetting parameters, including flow rate and jet velocity that are appropriate for the strength of a given soil profile. Work in this study presents a model for estimating pile jetting parameters based on results from laboratory and field testing. The model is based on idealization of the applied shear stresses of the jet and the shear strength of the soil. The model is applied to 19 field installations where the jetted depth ranged from 10-34 ft (3.05 m to 10.36 m). The field data yield ratios of jet flow rate to rate of pile volume insertion with time (Qw/Qp) of 6 to 17 with lower ratios associated with higher velocities. The proposed model yielded an estimation of Qw/Qp that was +/- 16% of the measured values.
  Authors: Gabr, Mohammed A.; Borden, Roy H.; Denton, Levi; Smith, Alex
  Authors: Gabr, Mohammed A.; Borden, Roy H.; Denton, Levi; Smith, Alex
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-1231
  Practice-Ready: Yes
• Economic Analysis of Onboard Monitoring Systems in Commercial Vehicles
  Abstract: On-board monitoring systems can be used in commercial vehicle operations to monitor driving behavior, with the goal of enhancing safety. While it is known that improved safety will produce an economic benefit to carriers, understanding how this benefit compares to system costs is an important factor for carrier acceptance. In addition to the safety benefits provided from using on-board monitoring systems, operational improvements may also have economic benefits. This research provides a better understanding of the economic implications of on-board monitoring systems from the perspective of the carrier through a benefit-cost analysis (BCA). In addition to the benefits of reduced crashes, benefits associated with electronic recording of hours of service, reduced mileage, and reduced fuel costs are considered. A sensitivity analysis is used and demonstrates that on-board monitoring systems are economically viable under a wide range of conditions. Results indicate that, for some fleet types, reducing crashes and improving HOS recording, provides a net benefit of close to $300,000 over the five-year expected lifespan of the system. Furthermore, when exploring additional benefits such as reduced fuel consumption and reduced vehicle miles, benefits can be upwards of seven times more than safety-related benefits. This research also shows that net positive benefits are possible in large and small sized fleets. Results can be used to inform policies for motivating or mandating carriers to use such systems, and to inform carriers regarding the value of system investment.
  Authors: Pitera, Kelly; Boyle, Linda Ng; Goodchild, Anne
  Authors: Pitera, Kelly; Boyle, Linda Ng; Goodchild, Anne
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation
  Session: 695
  Paper Number: 13-1259
  Practice-Ready: Yes
• Proposed New Performance Indicator: Vehicle Operating Cost Index due to Road Roughness
  Abstract: The New Zealand Ministry of Transport has stated that reducing transportation costs should be a key outcome of the use of the National Land Transport Fund. Road roughness contributes to the cost of transportation through factors such as fuel consumption, repairs and maintenance, and tyre wear. The cost due to roughness may be only a few cents per vehicle kilometre travelled (VKT), but with circa 20 billion VKT on the State Highway network each year the total cost can be significant. Currently the performance of the State Highway network is measured using the International Roughness Index (IRI) and Smooth Travel Exposure (STE); however, neither quantifies the cost due to roughness and neither are suitable surrogates. This paper presents a proposed new performance indicator, the Vehicle Operating Cost Index (VOCi) which returns the average vehicle operating cost due to road roughness per VKT. The VOCi has been applied to the entire New Zealand State Highway network, with results presented for each State Highway functional classification, at both the national and regional levels. Although nationally the magnitude and variability of VOCi reduces with increasing functional classification, as is consistent with appropriate stewardship of the asset taking account of the relative functional importance of the route, the same relationship does not always exist at the regional level. It should be noted, however, that the VOCi, like any other indicator of its kind, is only part of the information available to decision makers and will not negate the need to ‘drill-down’ to determine if there are any underlying reasons behind uncharacteristic values.
  Authors: Costello, Seosamh B.; Bargh, Louis S.; Henning, Theuns F. P.; Hendry, Matt
  Authors: Costello, Seosamh B.; Bargh, Louis S.; Henning, Theuns F. P.; Hendry, Matt
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 662
  Paper Number: 13-1265
  Practice-Ready: Yes
• Long-Term Performance of High-RAP Pavements: Case Studies
  Abstract: This paper presents the summary of findings of several case studies on the long term performance of high recycled asphalt pavement (RAP) sections. The goal of this study was to provide the paving community with documentation on the long term performance of high RAP roadway sections compared to that of virgin sections using available information. Roadway sections which contained more than 20% RAP and that had been in place for at least 10 years were identified from across the United States with the help of the local agencies. The long term performances of these various recycled sections were compared directly to mixtures made with similar virgin materials via measurements of distress criteria. These distress criteria included rutting, cracking, ride quality, and any overall performance rating that the local agencies used in evaluating their pavement sections. The virgin sections were placed in the same general location and time frame as the recycled sections. The high RAP sections on average tend to exhibit a lower ride quality, more cracking, and better rutting resistance than the virgin sections but the differences are not always statistically significant. The differences between the performance ratings for RAP and virgin pavements were within 5-10 percent. Overall, pavement sections utilizing high RAP perform at a level comparable to that of virgin sections in these case studies.
  Authors: Anderson, Evan; Daniel, Jo Sias
  Authors: Anderson, Evan; Daniel, Jo Sias
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 656
  Paper Number: 13-1264
  Practice-Ready: Yes
• Simple Methodology to Estimate Queue Lengths at Signalized Intersections Using Detector Data
  Abstract: This paper presents a simple methodology to estimate queue length on an approach to a signalized intersection. This method has a minimal set of data requirements specifically flow, occupancy, cycle length, and detector setback in contrast to prevailing methods that rely on estimating vehicle trajectories using detailed data defined on a per signal cycle basis. The key element of the algorithm is the estimation of two baseline occupancies that correspond to the relative position of the queue with respect to the detector location. The results of the algorithm have been evaluated using traffic simulation and also compared to field observations. The comparison of the queue estimates suggest that the detector location would be ideal to estimate queues, if under prevailing conditions the tail of the queue is routinely longer than the detector setback. For detectors with appropriate setback, queue estimates match well in both comparisons. This algorithm was developed as part of the Midtown in Motion project and is currently operational in the field, in New York City as one of the elements of the active traffic management.
  Authors: Chang, Jinil; Talas, Mohamad A.; Muthuswamy, Satya
  Authors: Chang, Jinil; Talas, Mohamad A.; Muthuswamy, Satya
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 261
  Paper Number: 13-1279
  Practice-Ready: Yes
• Simulation Study of Dedicated Bus Lanes on Jingtong Expressway in Beijing
  Abstract: Traffic congestion on urban roads is forcing city authorities to look at innovative transportation solutions. Bus Rapid Transit (BRT) systems are internationally recognized as an effective means to deal with the urban traffic congestion problems. The authors have undertaken a simulation study to pre-evaluate the effectiveness of a BRT plan on the Jingtong Expressway to ensure the effectiveness of traffic organization scheme. The simulation results showed that the dedicated bus lanes can greatly improve the carrying capacity and buses¡¯ operating speed though there may have some negative impact on the private vehicles. The comparison of the implementation effect was carried out between the pre-evaluated data (simulated data) and the field data after the implementation of dedicated bus lanes on Jingtong Expressway at May 24th, 2011. There is a good agreement between the pre-evaluated data and the field data. The results should encourage cities to consider dedicated bus lanes as one of the strategies to implement BRT service.
  Authors: Du, Yiman; Wu, Jianping; Zhou, Yang
  Authors: Du, Yiman; Wu, Jianping; Zhou, Yang
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 612
  Paper Number: 13-1293
  Practice-Ready: Yes
• Alicante Light Rail: Improving the Use of Existing Railway Lines
  Abstract: The TRAM Metropolitano de Alicante (TRAM) is a unique metric (1,000 mm) gauge system that was born as the first Spanish tram-train, but later lost the tram-train characteristic of sharing the railway tracks with conventional trains due to the evolution of the network. Nevertheless, it still operates in a quasi-tram-train way, as the tram-train vehicle runs partly on railway tracks using the railway signaling system and the rest of railway equipment.This quasi-tram-train operation leads to some specific design issues that are explained in this paper. Additionally, the paper presents a thorough description of the Alicante network, its development, its construction and operational costs, its operation and its demand.
  Authors: Novales, Margarita; Cerezo, Juan Antonio G.; Ortega, Roman
  Authors: Novales, Margarita; Cerezo, Juan Antonio G.; Ortega, Roman
  Year: 2013
  Document Type: Paper
  Subject: Public Transportation
  Session: 328
  Paper Number: 13-1300
  Practice-Ready: Yes
• Airport Pavement Missing Data Management and Imputation Using Stochastic Multiple Imputation Model
  Abstract: In practice, missing data in pavement condition databases has been one of the most prevalent problems in airport pavement management systems. Missing data present problems in pavement performance analysis and uncertainties in pavement management decision making. A number of data imputation approaches are available for handling missing data. This paper examines the limitations of the conventional data imputation methods, and proposed a Stochastic Multiple Imputation approach to overcome the major imitations of the conventional methods. A case study is presented to appraise the effectiveness of the proposed approach against three conventional data imputation methods, namely the substitution by mean method, the substitution by interpolation method, and the substitution by regression method. The roughness and friction data of a 4-km long runway pavement, and roughness data of a 4-km long taxiway were considered. The effectiveness of auxiliary variables in data imputation models is also demonstrated. The proposed stochastic Multiple Imputation method yielded the smallest errors for the roughness as well as friction data. The mean substitution method resulted in imputed values with the highest amount of deviations from the observed values, followed by the regression substitution method and the interpolation method. The analysis showed that the proposed Stochastic Multiple Imputation method out-performed the conventional methods in handling missing pavement condition data for pavement management decision making.
  Authors: Farhan, Javed; Fwa, Tien Fang
  Authors: Farhan, Javed; Fwa, Tien Fang
  Year: 2013
  Document Type: Paper
  Subject: Aviation; Energy; Environment
  Session: 675
  Paper Number: 13-1301
  Practice-Ready: Yes
• Characterization of Cracking Behavior of Continuously Reinforced Concrete Pavements Under Current Design Concept in Belgium
  Abstract: In Belgium, Continuously Reinforced Concrete Pavements (CRCP) are being used on large scale for more than forty years. Under the initial standard design concept an apparently very unfavourable cracking pattern develops with a high probability of clusters of closely spaced cracks. The standard design underwent several main changes over time with regard to longitudinal reinforcement rate, depth of the reinforcement layer, presence of an asphalt interlayer, pavement thickness, concrete mix, surface finishing and lane width. The current concept that has been used since 1995 is quite satisfactory since no major distresses have occurred since then. The primary objective of this paper is to investigate the crack spacing and crack width characteristics of the CRCPs under the current design concept. More specifically the focus is on the influence of the different reinforcement percentages on the early age cracking behaviour of CRCP. Several different approaches were used to analyse the crack spacing, especially, the probability of clusters of closely spaced cracks. Crack width data including the movement of the slab were also obtained by linear variable differential transformer (LVDT) measurements.
  Authors: Ren, Dongya; Houben, Lambert; Rens, Luc
  Authors: Ren, Dongya; Houben, Lambert; Rens, Luc
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 474
  Paper Number: 13-1302
  Practice-Ready: Yes
• Findings from International Scan on Managing Pavements and Monitoring Performance
  Abstract: Nine pavement and asset managers from the United States (U.S.) participated in an International Scan on Managing Pavements and Monitoring Performance. Four members were from state agencies, 3 from the Federal Highway Administration, 1 from a university technology transfer program and 1 consultant served as report facilitator. The scan team sought input on processes for implementing sustainable performance-based programs, effective communication methods for upper management and legislative support, agency cultures that support performance based programs, and techniques, tools, analyses and reporting that supports performance based management. Agencies selected for the visits had experience with managing their pavement networks under constrained budgets. The team traveled to New Zealand, Australia, Sweden, Netherlands and England and gathered information from 15 agencies.While the initial focus of the scan was on pavement management, the team found that some of the agencies conduct pavement management within an asset management framework. The findings are thus equally applicable to assets other than pavements. The key findings include the following: agency culture supports a long-term view towards managing pavements, elected officials understand their responsibilities as stewards of public funds, the road network is managed as a service provided to the traveling public, agency priorities are known and agency personnel are held accountable for their actions, agencies recognize the importance of building internal capacity and capabilities, and efficiency and value drive program delivery approaches.The scan team selected four focus areas that it believes have value in the U.S. In developing the long term view of managing assets, the visited agencies used long term financial plans and asset management plans. The scan team highly recommends that these plans be integrated into day-to-day practice in state and local highway agencies. A goal in the area of accountability is to foster the use of asset management plans and long term financial plans to optimize short-term investments to improve asset performance, but also report the unfunded long-term liabilities so elected and appointed officials understand the degree to which the transportation system is sustainable. Understanding unfunded liability will help elected and appointed officials, agency personnel at all levels, the public and the media realize the importance of sustainable asset management programs. Visited agencies discussed recurring independent assessments of the asset management plan and the long term financial plan to improve accountability, credibility and transparency with elected and appointed officials. Finally, the scan team saw the importance of people, processes and data within transportation agencies to develop and use the asset management and long term financial plans. Broad skills in the areas of engineering, contract administration, economics and accounting are needed.
  Authors: Zimmerman, Kathryn A.; Corley-Lay, Judith B.; Wlaschin, Butch; Tetreault, Richard M.
  Authors: Zimmerman, Kathryn A.; Corley-Lay, Judith B.; Wlaschin, Butch; Tetreault, Richard M.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 479
  Paper Number: 13-1312
  Practice-Ready: Yes
• Safety Effects of Converting Intersections to Roundabouts
  Abstract: This paper presents a before-after crash study of converting intersections to roundabouts in Denmark. General crash trends and regression-to-the-mean effects are accounted for by using correction factors estimated on the basis of 32 general comparison groups in this non-experimental observational study. 332 converted sites, 57 fatalities, 1,271 other injuries and 2,497 crashes are included in the study. Conversions have resulted in decreases in the numbers of crashes and injuries of 27% and 60% respectively. Crashes become less severe e.g. fatalities decreased by 87%, whereas property-damage-only (PDO) crashes only decreased by 16%.Safety effects vary between sites. The safety effect becomes better as the speed limit on the roundabout arms becomes higher. As the share of crashes at intersections, which are left-turn and angle crashes, becomes higher the safety effect becomes better. As the share of crashes at intersections, which are bicycle crashes, becomes lower the safety effect becomes better. Central islands more than two meters high produce better safety effects compared to lower central islands. Triangle or trumpet splitter islands produce better effects than no or parallel splitter islands. The numbers of bicycle crashes and injured cyclists have increased by 65% and 40% respectively due to the conversions. Cycle lanes next to the circulating lane have produced the worst safety effects for cyclists, whereas cycle paths without priority to cyclists resulted in the best effects. Colored cycle lanes and blue cycle crossings have produced worse safety effects for cyclists than comparable bicycle facilities without color.
  Authors: Jensen, Søren Underlien
  Authors: Jensen, Søren Underlien
  Year: 2013
  Document Type: Paper
  Subject: Design; Operations and Traffic Management; Safety and Human Factors
  Session: 626
  Paper Number: 13-1319
  Practice-Ready: Yes
• A new Set of Guidelines for Road Diet Conversions
  Abstract: Road diets, which convert four-lane highways to three-lane cross sections, are an innovative solution to address mobility and safety concerns under budgetary constraints. These improvements can assist in the development of multimodal corridors with minimal impact on automobile mobility, while retaining the original right of way. Past research has focused on evaluating road diet safety, but minimal guidance exists on determining when such conversions are appropriate from an operational perspective. The proposed guidelines focused on evaluating and comparing the operation of three- and four-lane roads at signalized intersections to provide basic guidance as to when the road diet conversion is appropriate. One of the important findings of this research is the expansion of the usable range for road diets. Prior experience has limited road diet application to roadways with ADTs less than 17,000 vehicles per day. This research identifies the importance of side street volumes and supports the utilization of road diets on roadways with volumes up to 23,000 vehicles per day. This paper provides comprehensive guidance for road diet evaluation including operational performance, correctable safety problems and identifies a list of evaluation elements that should be examined when in-depth analysis of alternatives is required.
  Authors: Stamatiadis, Nikiforos; Kirk, Adam
  Authors: Stamatiadis, Nikiforos; Kirk, Adam
  Year: 2013
  Document Type: Paper
  Subject: Design; Safety and Human Factors
  Session: 727
  Paper Number: 13-1321
  Practice-Ready: Yes
• Estimating Urban Freight Congestion Costs: Methodologies, Measures, and Applications
  Abstract: Congestion is a significant problem in America’s 439 urban areas. According to the Texas A&M Transportation Institute’s 2011 Urban Mobility Report (UMR), congestion caused urban Americans to travel 4.8 billion hours more and to purchase an extra 1.9 billion gallons of fuel for a congestion cost of $101 billion (1). The UMR informs decision-making at the federal, state, and local levels. In 2011, the Texas A&M Transportation Institute released the inaugural Congested Corridors Report (2), which produces congestion statistics for the 328 most congested directional corridors in the United States. With the documented growth in freight shipments, particularly in the trucking sector, researchers were interested in developing methodologies and measures to help inform policy-makers and decision-makers characterize the impacts of congestion on urban. These methodologies and measures were developed and incorporated into the UMR and CCR. The methodologies use inventory data from the Federal Highway Administration’s (FHWA’s) Highway Performance Monitoring System (HPMS) and historical speed data from INRIX® to estimate wasted time (delay in person-hours) and diesel fuel (gallons wasted), as well as the associated costs for trucks in urban congestion. The results and rankings appear intuitive, and this information provides an important dimension to these reports for characterizing congestion levels in urban areas and along congested corridors in America. This information will help to inform trucking stakeholders by quantifying the congestion impact to the trucking community. Researchers will continue to include truck delay, wasted fuel, and associated costs for urban area trucks in future releases of the UMR and CCR.
  Authors: Eisele, William L.; Schrank, David Lynn; Schuman, Rick; Lomax, Timothy J.
  Authors: Eisele, William L.; Schrank, David Lynn; Schuman, Rick; Lomax, Timothy J.
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 407
  Paper Number: 13-1344
  Practice-Ready: Yes
• Designing Bus Rapid Transit Facilities for Constrained Urban Arterials: A Case Study of the Webster Avenue SBS Running Way Design Selection Process
  Abstract: Providing Bus Rapid Transit (BRT) service on urban arterials can be a challenge for transportation agencies as they look to provide transit benefits within existing street infrastructure. Projects must provide high quality transit service while also supporting other important street needs such as pedestrian activity, traffic flow, on-street parking, and crash safety. Transportation agencies must make tradeoffs across different designs in ways that achieve a project’s goals but do not mire the early planning for the project in unneeded costs and delays. This paper describes the New York City Department of Transportation and MTA New York City Transit’s selection of the most appropriate on-street BRT running way design for Webster Avenue (US 1), a key north-south arterial in the central Bronx, based on a balanced, multi-modal set of criteria. Three BRT running way design alternatives - curbside, offset, and median bus lanes - were considered for Webster Avenue’s 70-foot wide right-of-way during the screening process. The four primary screening categories were transit operations, traffic operations, on-street parking / delivery curb space supply, and pedestrian benefits. Each design alternative was evaluated at two sample intersections that represented typical corridor conditions and the results were then expanded to provide a complete corridor evaluation. The evaluation found that the offset bus lane alternative most effectively balanced the transit and traffic needs along the Webster Avenue corridor while maintaining on-street parking and supporting pedestrian activity, making it the preferred corridor design.
  Authors: Beaton, Eric; Orosz, Theodore; Ernhofer, Oliver J.; Yuratovac, Donald; Reiss, Taylor; Bialostozky, Evan
  Authors: Beaton, Eric; Orosz, Theodore; Ernhofer, Oliver J.; Yuratovac, Donald; Reiss, Taylor; Bialostozky, Evan
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 226
  Paper Number: 13-1346
  Practice-Ready: Yes
• Outsourcing and Its Impact on Knowledge Management: Case Study of Kentucky Transportation Cabinet
  Abstract: Outsourcing various governmental functions has been a popular trend among state agencies for the last few decades for numerous reasons. For transportation departments, like the Kentucky Transportation Cabinet, the responsibility to provide a wide array of services and functions has led to the outsourcing of a number of functions traditionally done in-house. Once an agency has determined which functions will be conducted in-house and which functions will be outsourced, further thought must be given to the level of knowledge retention within the agency. As functions are outsourced and older workers retire, the amount of tacit knowledge contained within the organizational diminishes if there are not systems in places to capture and disseminate such knowledge. The primary goal of this assessment is to determine how outsourcing is affecting the Kentucky Transportation Cabinet and what trends may be emerging regarding future outsourcing. The secondary goal of this assessment is to determine if the Cabinet has any mechanisms designed to capture critical agency knowledge that may be lost when specific job functions are outsourced to the private sector. Some recommendations are offered regarding the implementation of knowledge management systems as knowledge management systems are integral for tapping into the collective intelligence and skills of employees.
  Authors: Gibson, J. Bryan; Wallace, Candice
  Authors: Gibson, J. Bryan; Wallace, Candice
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Data and Information Technology; Education and Training
  Session: 681
  Paper Number: 13-1376
  Practice-Ready: Yes
• Objectives for Setting Transfer Time Windows and Other Considerations for Transit Fare Policy
  Abstract: Transfers allow customers to board connecting services without the requirement to pay an additional fare to reach their destinations. As transfers are a core component of fare policy, it is important to select an appropriate transfer time window, defined as the time between the first and final boardings in a journey. The transfer time window selected is important to satisfy both revenue and customer needs.Different approaches can be utilized to derive transfer time windows. For example, a transfer time window can be derived by finding the trip possible with the longest duration on the transit network and setting a transfer time window that allows this trip to be taken on a single fare. Alternatively, a transfer time window can be set so that the time spent on the system is proportional to the fare paid. Unfortunately, both approaches yield relatively long transfer time windows if extreme travel scenarios are considered. To address this concern, an alternative approach was developed to consider more common trips. This analysis found that a transfer time window can be better derived by selecting commonly accessed destinations on the periphery of the transit network, calculating transfer time windows for each origin-destination pair for a weekday during the midday, and then taking the 85th percentile of the transfer time windows required for the origin-destination pairs identified in the sample. The transfer time window should then be rounded to the next 15- or 30-minute increment for communication purposes. Additional considerations when setting a transfer time window include revenue impacts, forward compatibility, congestion and delays, and enforcement. Finally, transfer time windows should be reviewed periodically as the transit system evolves to manage any revenue or customer risks due to changes in network design and travel patterns.
  Authors: Hui, William
  Authors: Hui, William
  Year: 2013
  Document Type: Paper
  Subject: Policy; Public Transportation
  Session: 421
  Paper Number: 13-1377
  Practice-Ready: Yes
• Assessment of Introductory Transportation Engineering Course and General Transportation Engineering Curriculum
  Abstract: Transportation engineering is a critical sub-discipline of the civil engineering profession as indicated by its inclusion in FE exam material, its overlap in most other specialty areas of civilengineering, and as recognized by the Transportation Research Board, Institute of Transportation Engineers, and the American Society of Civil Engineers. With increasing transportation workforce needs, low numbers of students entering the ‘pipeline’, and limited hours within undergraduate civil engineering programs, it is important to ensure civil engineering students receive adequate preparation and exposure to career opportunities in the transportation engineering field. As such, investigations into the status of transportationengineering within civil engineering programs and specifically the introductory transportation engineering course are essential for understanding the implications to the profession. This paper first presents a review of relevant literature and findings from a new survey of ABET accredited civil engineering programs (n=84 responses). The survey indicates that 87 percent of responding programs teach an introductory course, and nearly 80 percent require it in their undergraduate programs. There is significant variation in the structure of the introductory course (number of credit hours, lab requirements, etc.), and common responses regarding improvements that could be made include adding labs, requiring a second course, and broadening course content. In addition, nearly 15 percent of faculty teaching the introductory course did not have a transportation focus area. This finding should be investigated further, given that this course may be a civil engineering student’s only exposure to the potential in the profession.
  Authors: Turochy, Rod E.; Fricker, Jon D.; Hawkins, H. Gene; Hurwitz, David S.; Ivey, Stephanie; Knodler, Michael A.; Young, Rhonda Kae
  Authors: Turochy, Rod E.; Fricker, Jon D.; Hawkins, H. Gene; Hurwitz, David S.; Ivey, Stephanie; Knodler, Michael A.; Young, Rhonda Kae
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 684
  Paper Number: 13-1385
  Practice-Ready: Yes
• Measuring a Port’s Performance Using Economic Value of Commodities
  Abstract: The marine transportation system plays a significant role in the United States and other countries’ economies. Ports play a vital role in this system by serving as gateways to economic activities. Depending on their cargo, some ports are considered as primarily container ports, bulk cargo ports, or a combination of cargoes. In the US all of these types of ports compete for federal, state, local and private resources. The heterogeneity of cargo, however, makes port performance comparison difficult. Conventionally, tonnage or tons per mile statistics are used in port evaluations. These indicators, however, do not reflect the monetary value ports helps create or the economic significance of their service. To capture the heterogeneity of cargo and the economic role of ports, we propose using the value of commodities as a port performance measure. In fact, container ports already collect this data, but bulk ports typically do not. In this paper we use the Port of Duluth-Superior as a case study and illustrate that a bulk port’s cargo value can be assessed as well. Further, we propose estimating the total real value of a port’s cargo, as opposed to nominal value. We also estimate the average real dollar value per ton moved, which ports can use for value of service pricing. Both indicators, the total real value of cargo and the average real value per ton, can be used for relative ports performance comparisons. To assess a given port’s performance over time, we developed a third indicator - the real value index of a port. The proposed port performance measures are constructed on an annual basis, are port-specific and use publicly available data. The methodology used in the project can be potentially replicated for all US ports.
  Authors: Simkins, Zamira; Stewart, Richard D.
  Authors: Simkins, Zamira; Stewart, Richard D.
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Marine Transportation; Terminals and Facilities
  Session: 344
  Paper Number: 13-1395
  Practice-Ready: Yes
• Urban Transportation Greenhouse Gas Emissions and its Link with Urban Form, Transit Accessibility and Emerging Green Technologies: A Montreal case study
  Abstract: This research aims at estimating a GHG emission inventory at the household level using completely disaggregate trip data and taking into account all emitting modes. The impact of urban form (UF) and transit accessibility (TA) characteristics on household level GHG emissions is then quantified and compared to the impact of the introduction of emerging green technologies. Using a large and representative sample of household diaries, trip-level GHG emissions are estimated by combining different sources of data (origin-destination (OD) survey data, vehicle fleet characteristics, transit ridership data, etc.) and by using modeling tools (traffic assignment and GHGs models). Moreover, UF and TA indicators are developed and combined to generate neighborhood typologies. A simultaneous equation modeling framework is then implemented to investigate the link between UF, TA, socio-demographics, and travel GHGs, taking into account the well known “self-selection” issue. The potential impact of land use and transit supply strategies with emerging green technological scenarios is then compared. Our findings are consistent with the literature, more specifically we have found that the built environment (BE) attributes are statistically significant (10% increase in density, transit accessibility and land-use mix, results in 3.5 %, 5.8% and 2.5% reduction in GHG respectively), number of workers and retirees at the household level play an important role in the contribution to GHG emissions (102% increase by adding one worker and 51% decrease by adding a retiree to the household). Moreover, neighborhood types represented by the combined effects of UF and TS have important effects on GHGs. Also it is found that by replacing transit fleet by electric trains and hybrid buses, the share of transit GHGs would decrease by 32%. With respect to the private motor-vehicle fleet, if current trends persist, the constant improvement of car fuel consumption economy would reduce car GHGs by 7%. According to our results, the two most efficient strategies to reduce GHGs at the regional and household level seem to be the continuous fuel-efficiency improvement of the private motor-vehicle fleet and the increase of transit accessibility.
  Authors: Zahabi, Seyed Amir Hossein; Miranda-Moreno, Luis Fernando; Patterson, Zachary Rupert; Barla, Philippe
  Authors: Zahabi, Seyed Amir Hossein; Miranda-Moreno, Luis Fernando; Patterson, Zachary Rupert; Barla, Philippe
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: ADC70
  Paper Number: 13-1394
  Practice-Ready: Yes
• Bridge Building for Rural Developing Communities
  Abstract: Bridges to Prosperity (B2P) is a non-profit organization that focuses on being a primary depository and training centre for low cost, robust, long-span bridge structures for rural applications. Bridging the Gap Africa (BtGA), another non-profit bridge building organization, concentrates efforts on providing safe river crossings for rural communities in East Africa. The two organizations focus on building cable-supported bridges over impassable rivers to provide access to health care, education and market opportunities while decreasing risk of injuries or death.
  Authors: Rehm, Kelley; Bang, Avery
  Authors: Rehm, Kelley; Bang, Avery
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Safety and Human Factors
  Session: 703
  Paper Number: 13-1406
  Practice-Ready: Yes
• Exploring the performance limit of a single lane per direction Bus Rapid Transit Systems (BRT)
  Abstract: Despite its booming growth, the BRT industry is still far from reaching maturity. As trial-and-error and empirical techniques were largely used as insights for innovations in design, some BRT systems achieved great successes in terms of performance and became world-class flagships. Other systems would be most properly classified as busway systems requiring major improvements. In this paper we explore the performance of a single lane per direction no-overtaking BRT corridor, in terms of capacity and operating speed, by conducting a series of experiments that comprised the simulation of 324 alternative scenarios. In the simulation runs we varied demand levels, boarding and alighting rates, spacing of stations, vehicle loadings, quantity of berths per station, and traffic signal positioning in relation to stations. The qualitative analysis reveals that such a BRT system can achieve a capacity around 15,000 pass/h/dir along its critical section with an operating speed of 20 km/h. Preliminary statistical analysis enabled the estimation of a regression model representing the impact of BRT design elements on the operating speed. Our findings provide useful insights for designers of high-performance BRT corridors.
  Authors: Lindau, Luis Antonio; Pereira, Brenda Medeiros; Castilho, Rodrigo Alberto; Diogenes, Mara Chagas; Herrera, Juan Carlos
  Authors: Lindau, Luis Antonio; Pereira, Brenda Medeiros; Castilho, Rodrigo Alberto; Diogenes, Mara Chagas; Herrera, Juan Carlos
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 612
  Paper Number: 13-1412
  Practice-Ready: Yes
• Measuring and Benchmarking User Satisfaction with Transport
  Abstract: Increasing attention is being given to the ability of highway departments and metropolitan planning bodies to demonstrate the value for money of scarce public funds. Over time, this has led to a shift from accounting for the inputs to the system through to what is delivered. Ultimately however, the delivery of transport improvements is in the eye of the beholder – the public. It is therefore critical to connect the information provided on the performance of the transportation system to the public’s satisfaction with the outcomes of these interventions.This paper describes an initiative developed independently by local highways authorities in England which covers all aspects of investment except for inter-city motorway routes and rail investment (where they only have an advisory and not a management role). Despite there being no mandate for public satisfaction measures to be collected, a subscription based initiative has now been running for five years with over half of all highways authorities now engaged. This provides a rich longitudinal data set of satisfaction measures and information on citizen preferences.The paper presents information about the data collection methods, the findings and how the data is being used in benchmarking. It also extends the discussion into the next phase of the work which is examining the extent to which investment can be linked to system performance and in turn to user satisfaction. If successful this initiative could change the landscape for the incorporation of user preferences in transportation planning and management.
  Authors: Pinkney, Simon; Marsden, Greg
  Authors: Pinkney, Simon; Marsden, Greg
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Policy; MAP-21
  Session: 355
  Paper Number: 13-1407
  Practice-Ready: Yes
• Design of Geogrid-Reinforced Earth Walls: Transition of Limits and Critical Surfaces
  Abstract: The majority of design approaches or methodologies for reinforced soil walls or slopes are based on separately investigating the internal and external stabilities of the system. The internal stability is examined by satisfying the local stability of reinforcements at each level based on the predetermined critical slip plane (line of maximums) and the tributary area of each reinforcing layer. Recent research aimed at incorporating the contributions of the various elements of reinforced earth walls, some of which are mostly based on statistical correlations. The German code of practice for design/analyses of reinforced earth walls and slopes offers slightly different methodology for analyzing the internal stability of the reinforcement. It is mainly based on investigating numerous circular and random slip surfaces, within and beyond the reinforcement zone (internal and external), while accommodating the axial (resistance) forces provided by all reinforcement layers intercepting these surfaces. This paper presents some of the technical and design considerations and possible improvements on design methodology for reinforced soil walls and slopes. Of particular interest is the use of apparent cohesion concept in design of geosynthetic reinforced soil systems and the transition of limit equilibrium states (mobilization of actual state of equilibrium critical surfaces) for reinforced earth walls. The equivalent cohesion concept was used to transform reinforced soil masses into equivalent cohesive soil masses with friction capacity. Cases of analyses with comparisons between reinforced soil walls and the equivalent cohesive masses were performed and the results revealed very similar results between the two systems in terms of the safety of the walls.
  Authors: Al Mohd, Izzaldin Ayasrah; Ashteyat, Ahmed M.; Malkawi, Abdallah
  Authors: Al Mohd, Izzaldin Ayasrah; Ashteyat, Ahmed M.; Malkawi, Abdallah
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Geotechnology
  Session: 209
  Paper Number: 13-1422
  Practice-Ready: Yes
• Assessment of Adherence to the Condition of Proportionality in User Equilibrium Traffic Assignments with Uniquely Determined Route Flows
  Abstract: The standard formulation of static deterministic user equilibrium (UE) traffic assignment problem based on the criterion of Wardrop provides a unique solution in terms of link flows; however, route flows are not determined uniquely. Analyses based on an arbitrary choice among the infinite number of possible route flow solutions could cause inconsistencies or even controversies in applications. In 2010, a computationally efficient algorithm called Traffic Assignment by Paired Alternative Segments (TAPAS) was successfully implemented to identify UE route flows uniquely. So far, no effort has been made to assess adherence to the condition of proportionality in UE traffic assignment with uniquely determined route flows. In this paper, TAPAS was solved to obtain proportional UE route flows for the Chicago regional network in the closest proximity to uniqueness of the solution. Various assessments of adherence to proportionality are performed for a selected pair of alternative segments. The results show that route flows determined by TAPAS correspond closely to exact proportionality. Only minor differences occur between computed and exactly proportional UE route flows. Systematic characteristics of the plots for the two alternative segments show that TAPAS behaves properly according to the condition of proportionality. Insights from these empirical results may help transportation planning professionals to be aware of the magnitude of differences in UE route flows based on proportionality and to be able to differentiate uniqueness from non-uniqueness of route flows in UE traffic assignment. The results may also be useful to software developers in seeking improved adherence to proportionality of route flow solutions.
  Authors: Aungsuyanon, Aroon; Boyce, David; Ran, Bin
  Authors: Aungsuyanon, Aroon; Boyce, David; Ran, Bin
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 451
  Paper Number: 13-1423
  Practice-Ready: Yes
• Cementitiously Stabilized Materials Using Ultrasonic Testing
  Abstract: The effect of curing time, and compaction cementitiously stabilized materials (CSM) was studied using ultrasonic P-wave propagation. In general, the P-wave velocity measurements the mixtures increased with curing time. The trend between unconfined compression strength (UCS) with dry density or compaction water content was the same as the trend with P-wave velocity measurements. For stabilized fine-grained soils, there was a peak in P-wave velocity coinciding with the maximum dry density. The P-wave velocity and constrained modulus were strongly correlated to the UCS for CSMs. A model for prediction of UCS was proposed and verified. These test results provides insights for use of ultrasonic pulse velocity testing method for the determination of mechanical properties of CSM.
  Authors: Su, Zhipeng
  Authors: Su, Zhipeng
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 564
  Paper Number: 13-1435
  Practice-Ready: Yes
• On New Measures for Detection of Data Quality Risks in Mobility Panel Surveys
  Abstract: Multi-day and multi-period panel surveys are the state of the art methods to assess the changes in individual travel behavior. While being important for transportation planners these surveys are rather time consuming for participants and therefore might lead to erroneous and biased mobility data. Variability in the data quality significantly affects statistical analyses of mobility figures as well as common microscopic travel demand models which uses the mobility data as bases for activity plans. Supplementary to the well-known approach of weighting biases in key figures of mobility, our work focuses on measures for the detection of data quality differences between individual travel diaries. These quality measures address aspects of motivation loss at different stages of the survey. A classification approach based on these new quality measures helps to de-tect erroneous data and possible drop-outs. Quality measures are tested using recent data from the German Mobility Panel. For older participants above 60 years the quality measures show good classification results while for young participants below 35 years the quality measures look not effectual. Such an individual approach paired with the partial inspection and correction of travel diaries may be useful for microscopic travel demand modeling based on external activity chains.
  Authors: Wirtz, Matthias H; Streit, Tatjana; Chlond, Bastian; Vortisch, Peter
  Authors: Wirtz, Matthias H; Streit, Tatjana; Chlond, Bastian; Vortisch, Peter
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 223
  Paper Number: 13-1457
  Practice-Ready: Yes
• Effects on Service Quality Following Regulatory Reforms in Public Transport in Malta
  Abstract: This paper presents the results of a qualitative study on bus and car users in order to analyse the effects of a major reform in the public transport system on service quality. The case study of Malta is used following the decision by Government to implement a major reform which saw the islands’ monopolistic regime being replaced by competitive tendering. In this process Government introduced new service level requirements and obligations on the new operator, which started operations in July 2011. The study uses mixed methods to collect information about perceived quality of public transport services from non and infrequent bus users using a structured approach and perception of service quality from bus users using an exploratory approach. In both cases there are signs of improved service quality following the reform, however much needs to be done in areas related to punctuality, frequency, waiting time and trip duration. Through this study bus users were also able to identify the key factors of service quality. This study is intended to help operators to understand better the factors affecting bus use, the perception of bus service performance over a period of time and the need for necessary actions to support existing customers and attract new ones. This study highlights the importance of understanding the expectations of service level and the need for policies and measures that are mostly going to motivate those willing to change and reduce their use of the car.
  Authors: Attard, Maria
  Authors: Attard, Maria
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 761
  Paper Number: 13-1473
  Practice-Ready: Yes
• Risk Assessment of Stability Properties of Dynamic Network Loading
  Abstract: Over the past decades Dynamic Traffic Assignment models are increasingly used for online and offline applications of various urban environments for the successful and efficient deployment of traffic control strategies and the evaluation of traffic management schemes and policies. The stability of the dynamic network loading procedure is crucial for achieving the most accurate representations of traffic phenomena in congested urban networks, where the increase of congestion level often creates problems of discontinuity and system failure especially when the demand levels are temporally unstable and severe. In this paper a stability analysis is proposed in the context of evaluating the properties of the final resulting dynamic network loading solution through the evolution of time. The scope of this analysis is to provide practitioners and researchers a useful tool for the temporal statistical analysis and risk assessment of the dynamic representation of traffic conditions. The methodology of the proposed stability analysis is implemented on two reference networks. The results for the statistical analysis and the evaluation of the stability properties are discussed over an extensive sensitivity analysis of the simulation step to the selected stability measures.
  Authors: Papatzikou, Eleni; Stathopoulos, Antony
  Authors: Papatzikou, Eleni; Stathopoulos, Antony
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 451
  Paper Number: 13-1476
  Practice-Ready: Yes
• Approaches and Gaps in Weather-Responsive Traffic Management: U.S. and European Perspectives
  Abstract: Traffic management and operations during adverse weather is a major challenge for transportation agencies around the world. Weather is a common cause of crashes and delays on the highways everywhere, accounting for large number of fatalities and hours of delay every year in the US and Europe. Significant improvements have been made in the development and implementation of weather-responsive traffic management strategies to alleviate the impacts of weather, both in the US and Europe. These include weather and traffic data collection and integration, traffic analysis and modeling, human factors analysis and performance evaluation. This paper will describe the state-of-the practice in weather-responsive traffic management in the US and Europe including the types of strategies, systems and tools being used, their similarities, and their effectiveness in traffic operations. The paper will also describe the relevant research activities being undertaken in both countries and how they can coordinate and benefit from each other’s efforts. Finally, the gaps in current practices and research related to weather-responsive traffic management are identified, and recommendations on how these gaps can be filled are described
  Authors: Alfelor, Roemer; Billot, Romain; El Faouzi, Nour-Eddin; Pisano, Paul A.
  Authors: Alfelor, Roemer; Billot, Romain; El Faouzi, Nour-Eddin; Pisano, Paul A.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-1499
  Practice-Ready: Yes
• Global Emissions of Marine Black Carbon: Critical Review and Revised Assessment
  Abstract: Black carbon (BC) emissions from international shipping are significant and contribute to global and regional climate change, particularly in the Arctic. This paper reviews global estimates of international marine BC emissions, identifies differences in inventory methods, and proposes an approach for improving upon existing estimates. A critical review of the literature reveals that more refined, specific marine vessel BC emission factors (EFBC) are not generally accounted for in most global inventories. We find that EFBC are the single most important source of differences in inventories due to poor sensitivity to ship engine type, fuel quality, and engine load, and we propose a weighting framework that better encapsulates such effects. Using fuel consumption estimates from the International Maritime Organization (IMO) 2009 GHG report and updated EFBC, we estimate that shipping was responsible for about 184 thousand tonnes of BC in 2007. This estimate is 42 percent higher than the current IMO estimate, but comparable to recent studies informed by measured EFBC. We estimate that shipping contributed about 2,300 tonnes of BC in the Arctic in 2004, which is 90% higher than prevailing estimates. Our findings suggest that the international marine BC contribution is widely underestimated, and that improvements to major BC inventories can be made to reflect state-of-the-art data on marine EFBC.
  Authors: Wang, Haifeng; Minjares, Ray
  Authors: Wang, Haifeng; Minjares, Ray
  Year: 2013
  Document Type: Paper
  Subject: Environment; Marine Transportation; Terminals and Facilities
  Session: 217
  Paper Number: 13-1503
  Practice-Ready: Yes
• Evaluation of the Benefits of Diamond Grinding of CRCP in Texas
  Abstract: The paper discusses a study to evaluate the benefits of diamond grinding on a CRCP, used specifically for improving functionality in terms of surface macrotexture, skid resistance, roughness, and pavement noise. The effectiveness of diamond grinding in improving the above properties is calculated based on in-field observations. The effect of three different pre-existing conditions (carpet drag, burlap drag and transverse tining) on the effectiveness of the diamond grinding is also evaluated. The results of the analysis indicate that diamond grinding improved the surface macrotexture by 0.6 mm and skid resistance by about 60 %. The surface roughness of the diamond ground sections were on average appreciably reduced from 124 inch/mile to 80 inch/mile. An average overall reduction in noise level of 3.2 dBA was evident. A maximum reduction in the region of the noise frequencies (1,000 Hz to 2,500 Hz) was observed with a maximum noise reduction of 5.6 dBA at 1,600 Hz. The grinding operation produced a relatively uniform surface in terms of these properties despite the varying pre-existing conditions across the CRCP.
  Authors: Buddhavarapu, Prasad N. V. S. R.; Smit, Andre de Fortier; Trevino, Manuel; Banerjee, Ambarish; Prozzi, Jorge A.
  Authors: Buddhavarapu, Prasad N. V. S. R.; Smit, Andre de Fortier; Trevino, Manuel; Banerjee, Ambarish; Prozzi, Jorge A.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 711
  Paper Number: 13-1515
  Practice-Ready: Yes
• State of the Practice: Evaluation of Sediment Basin Design, Construction, Maintenance, and Inspection Procedures
  Abstract: To protect the nation’s surface waters from sediment-laden discharge, the proper selection, design, application, installation, and maintenance of erosion and sediment control practices on active construction sites are imperative. These practices will be required to comply with new, stricter regulations applied by the U.S. Environmental Protection Agency (USEPA) to control high sediment concentrations of stormwater discharges from construction sites. One means of control sediment-laden discharge is through the use of sediment basins. The purpose of this paper is to report results from a survey conducted to determine the state-of-the-practice for sediment basin design, construction, maintenance, and inspection techniques employed by state highway agencies (SHAs) nationwide. The survey consisted of 68 possible questions in six categories: (1) Background and Experience, (2) Design, (3) Construction, (4) Maintenance of Sediment Basins during Construction, (5) Inspection and Monitoring, and (6) Lessons Learned. A total of 37 responses (74% response rate) out of a total of 50 SHAs were received and analyzed.. The summary of the survey including lessons learned allow knowledge and experience to be transferred to practitioners that may have little or no experience with using sediment basins on construction projects. The survey shows that the typical design life of a sediment basin lifespan is between 6 months and 2 years, the generally accepted minimum storage volumes among most agencies is 3,600 cubic feet per acre of disturbed area draining to the basin, and thirteen agencies use flocculant additives to enhance the efficiency of sediment basins.
  Authors: Zech, Wesley Charles; Logan, Christopher P.; Fang, Xing
  Authors: Zech, Wesley Charles; Logan, Christopher P.; Fang, Xing
  Year: 2013
  Document Type: Paper
  Subject: Construction; Geotechnology
  Session: 600
  Paper Number: 13-1528
  Practice-Ready: Yes
• Kay County Shale Subgrade Stabilization Revisited
  Abstract: This paper presents a re-examination of a research project on US-77 in Kay County, Oklahoma concerning chemical stabilization of an 8-inch compacted shale subbase layer completed in 1983. The primary focus of this paper was to examine the changes in the pavement surface deflection and backcalculated modulus of the stabilized subbase layer within the project test sections over time.The original research project test sections were identified and tested with a trailer mounted Falling Weight Deflectometer (FWD) unit in August 2010. The FWD deflection survey performed in July 2000 and the original Benkelman beam deflection survey performed in June 1985 following the original pavement construction were used in this pavement analysis.The pavement had been overlain with two thin asphalt overlays. The FWD deflection data was normalized by ratio of the new thickness to the original pavement thickness so that the original Benkelman beam deflection data could be used. The pavement analysis uses the two-layer Hogg model and three-layer model in the Modulus 6.0 software to estimate the subgrade modulus and 8-inch stabilized subbase layer subgrade modulus respectively. The conclusions are the following: a) the pavement surface deflections indicate that the stabilized subbase layer sections have relatively stiff subgrade support, b) the three-layer model predicts a higher subbase layer modulus, and c) chemically stabilized subbase layers do not significantly lose strength or degrade with time and can be depended on as part of the structural section.
  Authors: Clarke, Christopher R.
  Authors: Clarke, Christopher R.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 694
  Paper Number: 13-1530
  Practice-Ready: Yes
• Maintenance Cost Justification for Chloride Treatment and Aggregate on Unsealed Roads
  Abstract: Treating aggregate surfaced roads with chloride dust suppressants or building them up by adding good quality surfacing aggregate is generally believed to reduce surface maintenance costs by creating a more durable surface. This paper quantifies reductions in routine blade maintenance costs by analyzing nearly seven years of cost data from the Johnson County (Wyoming) Road and Bridge Department.Over the past decade, Johnson County has experienced considerable oil and gas drilling, substantially impacting the county’s aggregate surfaced roads. Initial analyses assess the expenditures on the county’s unsealed road network’s highest volume roads, with an average of around 350 vehicles per day and a very high proportion of heavy trucks. The average annual cost of $9,167 per mile per year [$5,696/km-yr] to maintain these roads is high for an unsealed road, but the traffic volume is also high. The county’s maintenance cost data was used to perform a regression analysis with the time since aggregate addition and the time since calcium chloride treatment along with traffic and precipitation as independent variables to generate a model that predicts routine blade maintenance costs. This model predicts cost savings as a percent of the initial chloride treatment cost. Savings range from 24% at 200 vehicles per day to 79% at 650 vehicles per day. This represents only part of the benefits from these treatments, since lower user costs, safer roads, environmental benefits, and lowered aggregate replacement frequency are additional but currently unquantified benefits from good quality aggregate and dust suppression.
  Authors: Huntington, George; Ksaibati, Khaled
  Authors: Huntington, George; Ksaibati, Khaled
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 740
  Paper Number: 13-1543
  Practice-Ready: Yes
• Measuring Cyclists’ Exposure to Traffic Emissions Across Urban Cycling Facilities
  Abstract: This paper seeks to examine the relationship between traffic emissions and cyclists’ exposure to air pollution across a variety of cycling facilities within the Island of Montreal. The concentrations of two pollutants, ultra-fine particulate matter (UFP) and black carbon (BC) were measured at each second along a set of cycling routes. Two pairs of research assistants cycled on 25 unique routes over a five-week period. Each route was measured on four occasions: during the morning and evening peak periods on two separate days. Each route was approximately 25 ± 3 km for a total of approximately 600 km, covering nearly all 425 km of cycling facilities on the Island of Montreal as well as other common cycling corridors. A map of air quality across this network was generated for the morning and afternoon periods indicating significant differences in air pollution levels with the morning period associated with worse UFP and BC levels. This is attributed to traffic flows which are higher during the morning as well as lower ambient temperatures. Preliminary results show a significant correlation between cyclists’ exposure to UFP and measured traffic volumes (p<0.05), but even stronger correlation between exposure and the volume of trucks (p<0.01), indicating that vehicle composition may be an instrumental component of traffic data collection. Furthermore, results show that UFP exposure is inversely correlated to the distance between the bike path and the road (p<0.05) and that on average, bike lanes separated by a lane of parked cars have UFP levels 28.5% lower than without (p<0.05).
  Authors: Farrell, William; Weichenthal, Scott; Goldberg, Mark S.; Hatzopoulou, Marianne
  Authors: Farrell, William; Weichenthal, Scott; Goldberg, Mark S.; Hatzopoulou, Marianne
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1569
  Practice-Ready: Yes
• Low-Cost Techniques for Improving Surface Durability of Pervious Concrete
  Abstract: This paper presents the results of a laboratory study to improve the durability of pervious concrete using readily available and low cost techniques. Surface raveling of pervious concrete is a concern for long term use and remediation techniques have not previously been investigated. In this study a high void content pervious concrete was cured in worst case hot and dry conditions to produce poor surface durability. Pervious concrete mixtures included a traditional binder and one which included a super absorbent polymer for internal curing. Various remediation methods including overlaying with fresh pervious concrete, latex paint, epoxy, and a surface densifier were applied to the pavement before abrasion testing using the ASTM C944 rotary cutter method. Results showed that the internally-cured mixture had superior durability to the traditional mixture. Of the surface applied techniques, epoxy provided the best improvement in durability followed by latex paint and the densifier. Material analysis showed that modifying a mixture to include super absorbent polymer was the lowest cost option. On a poorly performing pervious pavement, latex paint or a thin overlay both had low material costs. The summary concludes that low-cost methods are effective techniques to improve the surface durability of pervious concrete.
  Authors: Kevern, John T.; Sparks, Joseph Dan
  Authors: Kevern, John T.; Sparks, Joseph Dan
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 287
  Paper Number: 13-1573
  Practice-Ready: Yes
• Bond Characteristics of Engineered Cementitious Composite Overlays
  Abstract: Rigid concrete overlays have been used for smoothing a damaged surface and/or restoring or improving the mechanical capacity of bridge-decks for many years. The superior ductility with high strength and improved durability characteristics suggest that Engineered Cementitious Composites (ECC) could be used as an attractive alternative to conventional overlay materials, and solutions if a strong mechanical bond is formed between the overlay and the substrate material. An experimental study was performed to evaluate the bond strength between ECC overlay and an ordinary concrete substrate with different types of surface textures including, smooth and rough. Micro-silica concrete (MSC), generally used as an overlay material, were also prepared as a control mixture. ECC and MSC overlay mixtures were cast over the concrete substrate to determine bonding performances. Two test methods; slant shear and splitting prism tests with MSC and two ECC mixtures were used. The experimental results show that when ECC is used as an overlay material, bond strength is significantly increased compared to those of MSC. Under compression loading (slant shear test), the bond strength properties of layered ECC-substrate concrete cylinder specimens is greater than the strength of substrate concrete with compressive strength of around 30 MPa. However, in the case of layered MSC-substrate concrete cylinder specimen, failure consistently occurs at the interface.
  Authors: Sahmaran, Mustafa; Yucel, Hasan Erhan; Al-Emam, Muhannad; Yaman, Ismail Ozgur; Guler, Murat
  Authors: Sahmaran, Mustafa; Yucel, Hasan Erhan; Al-Emam, Muhannad; Yaman, Ismail Ozgur; Guler, Murat
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 288
  Paper Number: 13-1578
  Practice-Ready: Yes
• Car-Truck Crashes in National Motor Vehicle Crash Causation Study
  Abstract: The National Motor Vehicle Crash Causation Survey (NMVCCS) provided in-depth investigative data on pre-crash factors and other characteristics of 5,470 crashes involving light passenger vehicles (“cars”). Within the dataset, 199 crashes, representing 79,721 crashes nationally, were collisions between cars and large trucks. Although only 3.6% of the NMVCCS, this data subset is a significant source of information about the genesis of car-truck crashes. This includes variables relating to crash configurations, critical reasons, associated factors, and conditions of occurrence. Findings supplement and generally corroborate those from the Large Truck Crash Causation Study. However, NMVCCS data are more recent and represent a wider range of crash severities. Cars were more likely than trucks to be the encroaching vehicle in car-truck collisions. Overall, 71.0% of assigned Critical Reasons (CRs) were to the car. Cars were more likely to be out-of-control prior to impact and to violate rights-of-way. Associated driver factors relating to impairment or aggressive acts were assigned more frequently to car drivers. Trucks were more likely to be assigned vehicle-related CRs and associated factors, however. Nationally, about 80% of truck-related fatalities occur in car-truck crashes, and car drivers contribute strongly to their genesis. Understanding their critical errors is essential for the development of effective countermeasures.
  Authors: Knipling, Ronald R.
  Authors: Knipling, Ronald R.
  Year: 2013
  Document Type: Paper
  Subject: Motor Carriers; Safety and Human Factors
  Session: 673
  Paper Number: 13-1548
  Practice-Ready: Yes
• Joint Impacts of Bus Rapid Transit and Urban Form on Vehicle Ownership Among Low-Income Households: New Evidence from Quasi-longitudinal Analysis in Bogota, Colombia
  Abstract: Bus Rapid Transit (BRT) has become popular as a means to provide reliable, non-automobile-based mobility and alleviate the impacts of rising traffic congestion in cities around the world. To date, however, there is little empirical evidence supporting BRT’s potential to meet these objectives, particularly for lower income households. Furthermore, there is limited knowledge regarding the urban form conditions necessary to support BRT. This research improves our understanding of BRT’s potential as an alternative to vehicle ownership for lower income households and provides new evidence on the role of urban form in supporting transit investment. We use a difference-in-differences research design to examine the change in vehicle ownership from before to after implementation of Bogotá, Colombia’s TransMilenio BRT system. Our results indicate access to TransMilenio’s main trunk system is not significantly related to the odds of vehicle ownership for lower income households except in neighborhoods with urban forms that are supportive of walking, bicycling, and transit use. Furthermore, we find access to TransMilenio’s feeder system is associated with an unexpected increase in the odds of vehicle ownership; however, that increase is overcome by supportive urban form. This research contributes to the debate about the transportation-urban form connection by demonstrating that urban form and transit access have a synergistic effect on vehicle ownership. Neglecting this synergy may lead to inconsistent or misleading results. Our findings also suggest that the benefits of BRT investment may not accrue to lower income households unless that investment is coordinated with policies to promote supportive urban form.
  Authors: Combs, Tabitha; Rodriguez, Daniel A.
  Authors: Combs, Tabitha; Rodriguez, Daniel A.
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 507
  Paper Number: 13-1550
  Practice-Ready: Yes
• Estimation of Time Rate of Settlement for Multilayered Clays Undergoing Radial Drainage
  Abstract: This paper demonstrates how the finite difference technique can be used to estimate the time-rate of settlement for soft, compressible clayey soils treated with prefabricated vertical drains, at sites where primary consolidation settlement is occurring in a multilayered system at varying rates. Semi-empirical methods based on surface settlement monitoring have typically been used to estimate the progression of primary consolidation settlement. However, interpretation of such methods can be problematic for multilayered soil profiles. For such sites, it is crucial to obtain a reasonable characterization of the foundation soils’ horizontal drainage properties and include these estimates in the time-rate of settlement projections. Field monitoring of subsurface instrumentation is extremely valuable in providing additional information regarding the consolidation behavior of different layers. When subsurface field measurements are coupled with the proposed numerical method, far more reliable projections are obtained. This paper focuses on how to integrate field and laboratory data with time-rate of settlement projections obtained from semi-empirical and finite difference methods to more accurately predict the time-rate of consolidation behavior of multilayered foundation soils.
  Authors: Farnsworth, Clifton B.; Bartlett, Steven F.; Lawton, Evert C.
  Authors: Farnsworth, Clifton B.; Bartlett, Steven F.; Lawton, Evert C.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Geotechnology
  Session: 622
  Paper Number: 13-1567
  Practice-Ready: Yes
• Method for Measuring the Ratio of In-Vehicle to Near-Vehicle Exposure Concentrations of Airborne Fine Particles
  Abstract: Human exposure to fine particulate matter (PM2.5) is causally linked to cardiovascular and pulmonary diseases. In-vehicle exposure may account for 10 to 20 percent of daily average exposure. However, exposure models are typically based on area-wide air quality data that poorly predict in-vehicle concentration. A practical method is demonstrated for conducting field measurements to quantify the ratio of in-vehicle to outside vehicle concentration (I/O) for a wide range of conditions that affect intra-vehicle variability in exposure concentration. A field data collection study design is developed based on sources of intra-vehicle variability in I/O, including ventilation air source, window status, fan setting, AC utilization, vehicle speed, road type, travel direction, and time of day. Three replicates of measurements were made for 16 combinations of these factors on 110 miles of roads comprised of eight one-way routes between typical commuter origin/destination pairs. Two portable particle monitors recorded in-vehicle and near-vehicle ambient concentrations on one minute averages for four particle size ranges. The comparability of the monitors was quantified. Near-vehicle concentrations varied with road type, time of day, and traffic conditions. The I/O ratio was approximately independent of near-vehicle concentration, and varied with window status, source of ventilation air (fresh or recirculation), and, for cases with recirculation and closed windows, fan setting and air conditioning use. The study design can be extended to additional vehicles to account for potential sources of inter-vehicle variability. Data such as collected here can be used to improve exposure simulation models.
  Authors: Jiao, Wan; Frey, H. Christopher
  Authors: Jiao, Wan; Frey, H. Christopher
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-1581
  Practice-Ready: Yes
• Exposing Minority Students to Transportation and STEM-Related Careers Through Summer Education Programs
  Abstract: The aging of the American workforce will lead to shortages in skilled workers throughout the country in the near future. Minorities are already underrepresented in the transportation industry, and without immediate intervention the conditions will not improve. To address the anticipated shortfall in skilled minority labor, the Federal Highway Administration, in coordination with the South Carolina Department of Transportation and the South Carolina State University, developed the Summer Transportation Institute (STI). In the Texas Gulf Coast region, the Center for Transportation Training and Research at Texas Southern University has introduced the transportation industry to minority high school students while emphasizing the importance of science, technology, engineering, and mathematics (STEM) skills in tomorrow’s workplace through summer education programs for nearly ten years. This study examines the core curriculum of those programs and discusses their potential applicability’s in other regions of Texas.
  Authors: Godazi, Khosro; Goodwin, Gwendolyn; Qiao, Fengxiang; Miller, Miller
  Authors: Godazi, Khosro; Goodwin, Gwendolyn; Qiao, Fengxiang; Miller, Miller
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 684
  Paper Number: 13-1584
  Practice-Ready: Yes
• Role of Heavy-Duty Freight Vehicles in Reducing Emissions on Congested Freeways with Elastic Travel Demand Functions
  Abstract: This paper investigates the relative impact of heavy-duty (HD) vehicles (primarily road freight) on the traffic congestion-emissions relationship. Unlike previous studies, this research explicitly considers the impacts of vehicle class travel demand elasticity on total emissions. Modeling results show that, even as a small share of the traffic volume, HD vehicles can contribute a large share of total pollution emissions, especially for particulate matter and nitrogen oxides. HD vehicle emissions rates are more sensitive to congestion than light-duty (LD) vehicle emissions rates, suggesting greater emissions benefits from congestion mitigation for these vehicles. Potentially lower travel demand elasticity to speed for HD vehicles further indicates vehicle class-specific benefits from congestion mitigation. The LD/HD vehicle differences suggest greater air quality benefits from vehicle class-targeted congestion mitigation or lane/capacity management strategies. HD vehicle travel demand elasticity is a key parameter to predict the net emissions effects of congestion. It is strongly recommended that analysis of emissions effects from congestion mitigation strategies include class-specific volume forecasts. Unfortunately, the estimation of HD vehicle travel demand elasticity values has received scant attention in the literature.
  Authors: Bigazzi, Alexander York; Figliozzi, Miguel
  Authors: Bigazzi, Alexander York; Figliozzi, Miguel
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-1607
  Practice-Ready: Yes
• Twitter Interactions as a Data Source for Transportation Incidents
  Abstract: Twitter is a microblogging platform that contains a large amount of publically accessible user generated content. This content consists of short social interactions between users. These interactions often describe day-to-day events, and can include location information, making them potentially suitable for use in transportation-related analysis. This paper evaluates the use of data from public social interactions on Twitter as a potential complement to traffic incident data. We compare incident records from the California Highway Patrol with Twitter messages related to roadway events over the same time period. Relationships between the two datasets are evaluated by visualizing the density of incidents and tweets that coincide near the same location. Additionally, the content of Twitter messages is weighted by its relevance to traffic incidents. This weighting is then compared to the time and space proximity of the message to an incident record to determine if more vivid Twitter messages may correspond to the presence of incidents. Twitter information is interesting because it is inexpensive, readily accessible, has broad geographic coverage, and provides a uniquely passenger-centric perspective. It is expected that this research will lead to a better understanding of the potential for information from Twitter to add context to other traffic measurements as a supplemental data source.
  Authors: Mai, Eric; Hranac, Rob
  Authors: Mai, Eric; Hranac, Rob
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 765
  Paper Number: 13-1636
  Practice-Ready: Yes
• Spatial Analysis of Maritime Accidents Using Geographic Information System
  Abstract: This paper aims to analyze the spatial distribution of maritime accidents occurring from January 1, 2002 to December 31, 2011 based on the Marine Casualties and Incidents module in Global Integrated Shipping Information System (GISIS). Geographic Information System (GIS), an effective and unique tool for spatial analysis with high visualization, is used to carry out the analysis. GIS makes it very convenient and easy to calculate the accidents happened in coastal areas by using the ¡°Selecting by location¡± function. Finally, the following two important results are reached. Firstly, hot spots are found. The area around the UK is the most dangerous, and coastal area of Eastern Asian countries, such as China, Japan, and Korea, and the Mediterranean Sea are the other two high risk areas. A comparison with a previous research is implemented to verify the result. It indicates that the results are more or less the same. Secondly, maritime accidents may not frequently happen in the open seas. However, there exists high probability for them to happen at coastal areas. 82.14% of the total accidents happened within 1 mile off the coastline and 90.04% within 2 miles.
  Authors: Huang, Dao-zheng; Hu, Hao; Li, Yi-zhou
  Authors: Huang, Dao-zheng; Hu, Hao; Li, Yi-zhou
  Year: 2013
  Document Type: Paper
  Subject: Marine Transportation; Pipelines; Safety and Human Factors
  Session: 637
  Paper Number: 13-1649
  Practice-Ready: Yes
• Modeling Air Quality Impacts of Feedstock Transportation for Cellulosic Biofuel Production in Tennessee
  Abstract: The efficiency of supply chain system of lignocellulosic biomass (LCB) feedstock is crucial to the development of the cellulosic biofuel industry. Moreover, the potential environmental impact of LCB feedstock transportation has also received increasing attention lately. This study first applied a spatial-oriented mixed-integer mathematical programming model linked to a GIS resource model to generate a least-cost solution of a typical feedstock supply chain system for a biorefinery with the capacity of 189.25 kl year-1 of biofuel in east, central and west Tennessee. The EPA’s MOVES model was then used to estimate the baseline emissions for 2010 in the study region and additional emissions generated from hauling feedstock. Results showed that switchgrass is more suitable than energy sorghum for biofuel production in Tennessee based on feedstock plant-gate cost and hauling emissions. Also, the biorefinery with the most economic feedstock cost and the least feedstock hauling emission is suggested to be sited in Robertson County, TN. The emissions of NOx, CO2, PM10, and PM2.5 from feedstock hauling in related counties increased by 0.12%, 0.04%, 0.15%, and 0.18%, respectively, when comparing with the emissions produced by existing overall traffics.
  Authors: Yu, Tun-Hsiang Edward; Larson, James A.; English, Burton C.; Fu, Joshua S.; De La Torre Ugarte, Daniel; Yun, Jeongran; Calcagno, Jimmy; Wilson, Bradly
  Authors: Yu, Tun-Hsiang Edward; Larson, James A.; English, Burton C.; Fu, Joshua S.; De La Torre Ugarte, Daniel; Yun, Jeongran; Calcagno, Jimmy; Wilson, Bradly
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-1650
  Practice-Ready: Yes
• Breaking into Bicycle Theft: Insights from Montreal, Canada
  Abstract: Many cities have adopted policies that promote walking and cycling because of their positive environmental, economic, and social benefits. As bicycles become a more popular form of transportation and more bicycles are out on the road, planners and transportation researchers will have to consider not only how to create urban spaces that encourage cycling, but also how to discourage bicycle theft. Currently, bicycle theft often goes unnoticed and is largely unchallenged. The present research brings attention to this issue by providing a narrative on bicycle theft in Montreal, Quebec, Canada. A bilingual online bicycle theft survey was designed for this purpose and answered by 2,039 Greater Montreal residents. Summary statistics address ‘who’, ‘what’, ‘where’, ‘how’, and ‘when’ questions, a logit model determines variables associated with theft, and thematic maps compare experienced and expected theft between sub-regions. Half of respondents have had at least one bicycle stolen. Cyclists most frequently had their bicycles stolen in the downtown area. While, bicycles locked with U-locks, expensive bicycles, and those owned by women, are less likely to have been stolen. Satisfaction with bicycle parking availability and security tends to be low, and many cyclists are willing to pay for improved secure bicycle parking. Findings from this study can not only be useful to better understand and ultimately decrease bicycle theft in Montreal, but can also be beneficial for cyclists, police, and policy makers in other cities aiming to decrease bicycle theft as it highlights new findings in this unexplored area of research.
  Authors: van Lierop, Dea Suzanne; Grimsrud, Michael A.; El-Geneidy, Ahmed M.
  Authors: van Lierop, Dea Suzanne; Grimsrud, Michael A.; El-Geneidy, Ahmed M.
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Planning and Forecasting; Policy
  Session: 556
  Paper Number: 13-1670
  Practice-Ready: Yes
• Case Studies in Innovative Quality Assurance Methods for Alternative Delivery Projects
  Abstract: This paper presents the results of a multiple-case study, designed to explore, reveal, and consider evolving techniques used for managing quality assurance systems, especially in cases of alternative forms of delivery, such as construction manager/general contractor (CMGC), Design-Build (DB), and Pubic Private Partnerships (PPP) forms. The study discovered many notable quality assurance methods, including methods that take advantage of design-phase contractor involvement and methods that respond to the increasing use of non-agency designers.The study of ten distinct projects that cross four different project delivery methods found eighteen notable quality assurance methods that generally are not applied in the traditional Design-Bid-Build (DBB) form of contracting. These methods exist in both the pre-award and post-award phases of the projects, and several of the methods were found to be used on more than one form of project delivery. These innovative quality assurance methods may be viewed as tools that a project manager should consider when developing a whole quality assurance system on either a traditional DBB project or on a project that uses one of the alternative forms of contracting. Or—these methods may be used as starting points for further quality assurance innovations.
  Authors: Sillars, David N.; Harman, Landon
  Authors: Sillars, David N.; Harman, Landon
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design
  Session: 244
  Paper Number: 13-1695
  Practice-Ready: Yes
• Indian Reservation Safety Improvement Program: Methodology and Case Study
  Abstract: The need to reduce fatal and injury crashes on Tribal lands has been recognized for years. The U.S. has realized a decline in fatal crashes over the past several years but fatal crashes continue to increase on Tribal lands. Little progress has been made in improving safety on Tribal lands. Limited resources and lack of coordination across jurisdictions has made it difficult for Native American communities to address their roadway safety concerns. The rural nature of many of their roadways and lack of crash data has also made it difficult for Tribes to implement an effective safety improvement program. A methodology that is able to address these challenges is presented in this paper to assist Tribes in reducing fatal and injury crashes. The proposed methodology has been implemented successfully in the Wind River Indian Reservation. Key to the success of such a process is collaboration among safety stakeholders, namely the state departments of transportation, Tribal leadership, Local Technical Assistance Program (LTAP), Tribal Technical Assistance Program (TTAP), Bureau of Indian Affairs (BIA), and local and Tribal law enforcement.
  Authors: Shinstine, Debbie; Ksaibati, Khaled
  Authors: Shinstine, Debbie; Ksaibati, Khaled
  Year: 2013
  Document Type: Paper
  Subject: Policy; Society
  Session: 333
  Paper Number: 13-1697
  Practice-Ready: Yes
• Adult Learners: Principles, Barriers, and Best Practices
  Abstract: Abstract:The practice of teaching and educating adults, commonly known as andragogy, touches many areas of workforce education. Programs such as the Tribal Technical Assistance Program (TTAP) and Local Technical Assistance Program (LTAP) and others have adults as their primary audiences. Bringing 30+ years of experience as a practitioner and a researcher, the author will give valuable information about adult education and its basic principles, barriers and best practices as well as the impact of societal and generational changes on adult education. This session will provide summit attendees current valuable and practical practices which could be implemented in their next training sessions or classes. With a continued “Graying of America” and increased emphasis on learning throughout one’s life span, all educators, both formal and informal would benefit from knowing more about the topic of adult education. Scholars such as Knowles, Merriam, Brookfield, and Mezirow have contributed valuable research in this field. Adults are different from youth with different needs or reasons for pursuing education as well as differing levels of motivation. Adults also seek to learn what they have identified as important, look for immediately applicable learning as well as focusing more on problem centered learning rather than subject centered learning. Generational theory in relationship to adult education will be discussed as it relates to tailoring of educational approaches. This paper will provide best practices to increase the effectiveness of the teaching/learning process.
  Authors: Self, Mary Jo
  Authors: Self, Mary Jo
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 504
  Paper Number: 13-1722
  Practice-Ready: Yes
• Operations of a Taxi Fleet for Advance Reservations Using Electric Vehicles and Charging Stations
  Abstract: This research studies the operations of a taxi fleet that uses electric vehicles to cater solely for trips with advance reservations. The idea is for a dispatch system to chain multiple trips to form a route and offers it to a taxi driver. We describe this unique problem as the Singapore Taxi Advance Reservation with Electric vehicles (STARE) problem. As electric vehicles have limited running time before recharging, the problem of minimizing number of taxis used is formulated as a customized Paired Pick-up and Delivery Problem with Time Window and Charging Station (PPDPTWCS). A two-phase heuristic approach has been proposed to solve the PPDPTWCS. Numerical experiments have been performed to compare three initial solution approaches (namely nearest neighbor, sweep and earliest time insertion heuristics), effect of different recharging plans and different number of Charging Stations (CSs), using the simulated Central Business District (CBD) network in Singapore. The results show that (i) the earliest time insertion heuristic produces the best initial solutions; (ii) longer maximum running time before recharging results in a smaller fleet of taxi used, fewer visits to the CSs, longer running time per taxi and higher average revenue per driver; and (iii) changing the number of CSs has little effect on the system’s performance measures.
  Authors: Wang, Hao; Cheu, Ruey Long
  Authors: Wang, Hao; Cheu, Ruey Long
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 648
  Paper Number: 13-1717
  Practice-Ready: Yes
• Coherent Approach for Modeling and Nowcasting Hourly Near-Road Black Carbon Concentrations in Seattle, Washington
  Abstract: With growing awareness for near-road air pollution and an increasing population of pedestrians, it is imperative to “nowcast” near-road air quality conditions to the general public, which necessitates the efforts of building hourly predictive models with ease of use and satisfactory accuracy. This study demonstrates a coherent approach to model the hourly near-road Black Carbon (BC) concentrations with on-road factors and meteorological conditions using datasets from two urban sites in Seattle, Washington. With Bayesian Model Averaging (BMA) method, the optimal set of regressors is determined. Three different model structures are further developed and compared by goodness-of-fit. An innovative approach is proposed to translate wind direction from numerical values to categorical variables with statistical significance. By modeling the autocorrelation within the BC time series using AR(1) component, the developed approach yields a satisfying prediction accuracy. The conditional heteroscedasticity and heavy-tailed distribution within the residuals are successfully identified and modeled by the General Auto Regressive Conditional Heteroscedasticity (GARCH) model, which provides valuable insights to the interpretation of prediction results. The approach demonstrated in this study presents an efficient and valuable solution to selecting and fine-tuning a nowcasting model to be implemented onto online platforms for near-road BC nowcasting. A comparison between the two study sites also reveals the effectiveness of freight regulation for mitigating environmental impacts from the heavy truck fleet.
  Authors: Yu, Runze; Liu, Xiaoyue (Cathy); Wang, Yinhai
  Authors: Yu, Runze; Liu, Xiaoyue (Cathy); Wang, Yinhai
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-1792
  Practice-Ready: Yes
• Design and Modeling of Real-Time Shared-Taxi Dispatch Algorithms
  Abstract: Taxi is certainly the most popular type of on-demand transportation service in urban areas because taxi dispatching systems offer more and better services in terms of shorter wait times and travel convenience. However, a shortage of taxicabs has always been critical in many urban contexts especially during peak hours and taxi has great potential to maximize its efficiency by employing shared-ride concept. There are recent successes in real-time ridesharing projects that are expected to bring substantial benefits on energy consumption and operation efficiency, and thus it is essential to develop advanced vehicle dispatch algorithms to maximize occupancy and minimize travel times in real-time. This paper investigates how taxi services can be improved by proposing shared-taxi algorithms and what type of objective functions and constraints could be employed to prevent excessive passenger detours. Hybrid Simulated Annealing (HSA) is applied to dynamically assign passenger requests efficiently and a series of simulations are conducted with two different taxi operation strategies. The simulation results reveal that allowing ride-sharing for taxicabs increases productivity over the various demand levels and HSA can be considered as a suitable solution to maximize the system efficiency of real-time ride sharing.
  Authors: Jung, Jaeyoung; Jayakrishnan, R.; Park, Ji Young
  Authors: Jung, Jaeyoung; Jayakrishnan, R.; Park, Ji Young
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 354
  Paper Number: 13-1798
  Practice-Ready: Yes
• Dynamic Collection Scheduling Using Remote Asset Monitoring: Case Study in Charity Sector
  Abstract: In the waste collection sector, remote sensing technology is now coming onto the market, allowing waste and recycling receptacles to report their fill levels at regular intervals. This enables collection schedules to be dynamically optimised to better meet true servicing needs, so reducing transport costs and ensuring that visits to clients are made in a timely fashion. This paper describes a real-life logistics problem faced by a leading UK charity in servicing its textile and book donation banks and its High Street stores using a common fleet of vehicles with varying carrying capacities. This gives rise to a vehicle routing problem whereby visits to stores are on fixed days of the week, with time window constraints, and visits to banks (fitted with remote fill monitoring technology) are made in a timely fashion to avoid them becoming full before collection. A tabu search algorithm was developed to provide vehicles routes for the next day of operation, based on maximising profit. A longer look-ahead period was not considered on the basis that donation rates to banks are highly variable. The algorithm included parameters specifying the minimum fill level (e.g. 50%) required to allow a visit to a bank and a penalty function used to encourage visits to banks that are becoming full. The results showed that the algorithm increased profit by up to 3.6% with best performance obtained the more variable the donation rates.
  Authors: McLeod, Fraser Neil; Erdogan, Gunes; Cherrett, Tom; Bektas, Tolga
  Authors: McLeod, Fraser Neil; Erdogan, Gunes; Cherrett, Tom; Bektas, Tolga
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 268
  Paper Number: 13-1814
  Practice-Ready: Yes
• Transatlantic Dual Master's Degree Program in Transportation and Logistics Systems: First Two Years of Implementation
  Abstract: In August 2010, The University of Texas at El Paso (UTEP), Czech Technical University (CTU) and University of Zilina (UNIZA) jointly launched the Transatlantic Dual Masters Degree Program in Transportation Science and Logistics Systems. Under this program, a graduate student will spend one a year study at UTEP and another year at CTU or UNIZA. Upon the completion of the two-year program, the study will earn two master degrees. This project requires two years of preparation that lead to a successful proposal submitted to the funding agencies in U.S. and the European Union, followed by one year of administrative preparation before the actual student exchanges began in August 2011. The first cohort of eight students has successfully completed the program in June 2012. This article reports the sequence of events that led to proposal submission and award, major issues surfaced and challenges overcome during administrative preparation phase. This paper also documents the experiences of the professors and students who have participated in this program, and shares the key factors that have led to the successful implementation in the initial years.
  Authors: Cheu, Ruey Long; Carlos, Ferregut; Bína, Ladislav; Novakova, Helena; Horak, Tomas; Novak, Andrej; Hudak, Anton; Aguirre-Covarrubias, Sandra
  Authors: Cheu, Ruey Long; Carlos, Ferregut; Bína, Ladislav; Novakova, Helena; Horak, Tomas; Novak, Andrej; Hudak, Anton; Aguirre-Covarrubias, Sandra
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 684
  Paper Number: 13-0133
  Practice-Ready: Yes
• Event-Based Modeling of Driver Yielding Behavior to Pedestrians at Two-Lane Roundabout Approaches
  Abstract: Unlike other types of controlled intersections, drivers do not always comply with the “yield to pedestrian” sign at the roundabouts. This paper aims to identify the contributing factors affecting the likelihood of driver yielding to pedestrians at two-lane roundabouts. It further models the likelihood of driver yielding based on these factors using logistic regression. The models have been applied to 1150 controlled pedestrian crossings at entry and exit legs of two-lane approaches of six roundabouts across the country. The logistic regression models developed support prior research that the likelihood of driver yielding at the entry leg of roundabouts is higher than at the exit. Drivers tend to yield to pedestrians carrying a white cane more often than to sighted pedestrians. Driver traveling in the far lane, relative to pedestrian location, have a lower probability of yielding to a pedestrian. As the speed increases the probability of driver yielding decreases. At the exit leg of the roundabout driver turning right from the adjacent lane have a lower propensity of yielding than drivers coming from other directions. The findings of this paper further suggest that although there has been much debate on pedestrian right-of-way laws and distinction between pedestrian waiting positions (in the street versus at the curb), this factor does not have a significant impact on driver yielding rate.The regression models also quantify the effect of each of these factors on propensity of driver yielding. The models include variables which are specific to each study location and explain the impact size of each study location on probability of yielding. The models generated in this research will be useful to transportation professionals and researchers interested in understanding the factors impact driver yielding at modern roundabouts. The results of the research can be used to isolate factors that may increase yielding (such as lower roundabout design speed), and can feasibly be incorporate into microsimulation algorithms to model driver yielding at roundabouts.
  Authors: Salamati, Katy; Schroeder, Bastian J.; Geruschat, Duane R.; Rouphail, Nagui M.
  Authors: Salamati, Katy; Schroeder, Bastian J.; Geruschat, Duane R.; Rouphail, Nagui M.
  Year: 2013
  Document Type: Paper
  Subject: Design; Operations and Traffic Management; Safety and Human Factors
  Session: 542
  Paper Number: 13-0419
  Practice-Ready: Yes
• Automatic Network-Level Identification of Sight Distance Values from Existing Data Sets
  Abstract: Many highways were built years before tools like geographic information systems (GIS) and computer aided design were available. Therefore, keeping track of “legacy infrastructure” design parameters is a difficult task since, often, the only information contained on GIS datasets available to decision makers is the location of the highway centerline, along with other asset management information such as shoulder presence, pavement type, and roadside features. The lack of information in GIS datasets about basic design characteristics, such as radius and centerline elevation, means that field surveys are required in order to determine if a highway meets the latest design guidelines. Frequently, field procedures can be not only labor-intensive, but also cost-prohibitive, especially in times of economic constraints.This paper focuses on the use of existing photographic logs commonly owned by transportation agencies to automate the process of computing the sight distance available, from a vertical alignment point of view, along an entire route. While the analysis presented is focused on identifying road segments in need of a no passing zone, results from the methodology discussed can also be used to identify segments where advisory speeds need to be established, as well as those segments where posted speeds should be increased/decreased in order to improve safety. Through the application of the methods presented in this paper, the authors demonstrate how value can be added to existing datasets that were originally collected for completely different purposes.
  Authors: Santiago-Chaparro, Kelvin Roberto; Chitturi, Madhav V.; Bill, Andrea R.; Noyce, David A.
  Authors: Santiago-Chaparro, Kelvin Roberto; Chitturi, Madhav V.; Bill, Andrea R.; Noyce, David A.
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-0054
  Practice-Ready: Yes
• Automated Collection of Cyclist Data Using Computer Vision Techniques
  Abstract: One of the main challenges in conducting detailed analysis of cyclist behavior is the lack of reliable data. Collecting data through manual methods is a labour-intensive and time consuming process. Two of the important areas of cyclist data collection are volume counts and average speed measurement. A volume count is important as it provides the basis for necessary exposure measures and conveys essential information of traffic patterns. It can also serve as a performance measure of the facility. Cyclist speed data is used for traffic control and safety studies. Video sensors, when complemented with computer vision can offer a promising approach for the automated collection of traffic data. The approach is characterized by the wealth of data they can capture, store and analyze. Through the application of computer vision techniques, it is possible to obtain precise spatial and temporal measurements of the road-users in a resource-efficient way. This paper demonstrates the use of a set of computer vision techniques for the automated collection of cyclist data. The cyclist tracks obtained from video analysis are used to perform screen line counting as well as cyclist speed measurements. The applications are demonstrated using a real-world data set from a roundabout in Vancouver, British Columbia. Further analysis was conducted on the mean speed of cyclists with regards to several factors such as the travel path, helmet usage, and group size. The motivation of this research is to improve the understanding of cyclists’ behavior and how it varies under different conditions. Several conclusions can be drawn from the analysis of cyclist speed behaviour. Group size, travel path, lane position and helmet usage were found affect the cyclist mean speed. Single cyclists had a slightly, but significantly higher mean cycling speed compared to group cyclists. The mean cycling speed was highest for the cyclists using the road rather than the sidewalk. The mean cycling speed decreases for non-helmet users.
  Authors: Zaki, Mohamed H.; Sayed, Tarek; Cheung, Andrew
  Authors: Zaki, Mohamed H.; Sayed, Tarek; Cheung, Andrew
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0745
  Practice-Ready: Yes
• Performance Measures for Bridge Preservation
  Abstract: A study of performance measures for bridge preservation is reported. Performance measures for bridge preservation use National Bridge Inventory (NBI) general condition ratings, element-level condition states, and average costs to identify bridges to preserve, to determine the annual needs in preservation work and resources, and to quantify the impacts of preservation programs on bridge conditions and program costs. Proposed measures of performance for bridge preservation are demonstrated for the inventory of State-owned bridges in Colorado.
  Authors: Hearn, George
  Authors: Hearn, George
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 620
  Paper Number: 13-1551
  Practice-Ready: Yes
• Otta Seal Experience in Nepal
  Abstract: Otta Seals have been adopted in many countries as a low-cost pavement sealing alternative for durable and smooth roads. However, this pavement surfacing option for low volume roads is not yet universally accepted, and its effectiveness is disputed, because of its varied performance. This paper assesses the Otta Seal experience in Nepal for the last ten years, for both local and strategic roads in different geographic terrains – covering the hills and plains of Nepal. It addresses aspects of Otta Seal technology in relation to design, construction, cost and in-service performance, as well as its acceptance by the stakeholders, including the beneficiaries. The stakeholder acceptance has been affected by the early deterioration of the road surface in some instances, mainly attributable to inadequate design, poor quality of construction and inexperience with a new road technology. Road geometry, vehicle speed, and axle loads are other factors which have seriously affected durability. However, overall the performance of the pavements has been considered to be acceptable. The factors contributing to early failures require further discussion and research to help build ownership of this low-cost paving technology among road agencies.
  Authors: Joshi, Surendra Govinda
  Authors: Joshi, Surendra Govinda
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design; Pavements
  Session: 245
  Paper Number: 13-1627
  Practice-Ready: Yes
• Certificate Program in Transit Management and Operations
  Abstract: The overarching goals of this project are to provide college students with an educational and hands-on experience regarding employment opportunities in the public transit industry and to fully prepare them to enter the transit workforce. The project is intended to serve as a model for other transit operators and universities around the country where similar interests exist. While working toward a degree, students will elect to earn a “Certificate in Transit Management and Operations”, awarded jointly by UMass Transit, UMass Transportation Center, and CTTransit. Requirements include classroom preparation and on the job training. Each student will complete a 400 hour internship split between UMass Transit and CTTransit, or transit facilities of similar size. In addition, students will be expected to enroll in a minimum of fifteen credits (five courses) and various non-credit course offerings. The certificate should be earned over a 12 to 18 month period while the student is enrolled as an undergraduate or graduate. Upon graduation, they will be better prepared to consider professional job opportunities in the transit industry with transit operators and transportation.
  Authors: Byam, Allan; Oldread, Krystal
  Authors: Byam, Allan; Oldread, Krystal
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 504
  Paper Number: 13-1059
  Practice-Ready: Yes
• Twenty-Five Years of Performance: Validation of Illinois Mechanistic-Empirical Pavement Design on US-20 and US-50
  Abstract: In the summer of 1986 the Illinois Department of Transportation (IDOT) built four demonstration sections to validate the proposed mechanistically-based pavement design procedures. Multiple variables were taken into consideration in order to determine a valid correlation between pavement design inputs and pavement performance. After 25 years of service, these sections have provided great value to IDOT in the development of the pavement design procedures, policies and standards, and in general a better understanding of the mechanics of pavement performance. The knowledge acquired from the four sections supports IDOT’s practice in the use of performance graded binders, joint spacing in jointed concrete pavements, jointed concrete and full-depth hot-mix asphalt pavement thickness design, and subgrade selection. This study has validated IDOT’s mechanistic pavement design procedure, proving that the theory behind the 1986 design was correct. Since then, these sections and extensive laboratory testing and investigation have allowed IDOT to further refine the mechanistic pavement design procedure to include more accurate material properties. In addition to improving design procedure, having 25 years of data and observing the deterioration and rehabilitation of certain sections have allowed IDOT to fine tune the maintenance models to improve pavement type selection between flexible and rigid alternatives.
  Authors: Pava, Juan David
  Authors: Pava, Juan David
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 267
  Paper Number: 13-1036
  Practice-Ready: Yes
• Chicago’s Congestion Parking Tax: Early Evaluation
  Abstract: In recent years, congestion pricing has come to the forefront as a method of traffic mitigation. Chicago implemented a congestion parking tax increase, effective January 2012, on commercial lots and garages above a certain threshold. This study aims to provide a model framework for early impact analyses of congestion charging and parking schemes. A cluster-based system of metrics, focusing on publicly available transportation, economic and public health data for the study area of downtown Chicago, is employed.The “control variables” of employment figures and gas prices show relatively small change, indicating reasonably stable macroeconomic conditions in the region. It is found that municipal parking tax revenues have increased over 20 percent versus a year ago, although consumers are bearing only a small proportion of the tax increase. Arterial speeds downtown have improved, but some expressways passing through downtown have seen decreases in speed, possibly due to higher levels of unaffected through traffic on these roads. The public health variables of pedestrian crash incidents and emission levels have fallen.Chicago’s congestion parking scheme therefore appears to have caused no net negative results and indeed some positive results. These indicate a need for further research to better understand the relationship between the program and component metrics.
  Authors: Lai, Andrew; Newmark, Gregory L.
  Authors: Lai, Andrew; Newmark, Gregory L.
  Year: 2013
  Document Type: Paper
  Subject: Finance; Operations and Traffic Management; Policy
  Session: 294
  Paper Number: 13-0079
  Practice-Ready: Yes
• Investigation of Very Early Opening Strength Portland Cement Concrete Pavement Repair with the Application of Maturity Testing
  Abstract: The repair of concrete pavement due to utility cuts or deterioration on St. Louis County, Missouri right-of-way consisted of an evaluation of current materials, construction methods and specifications to deliver a durable concrete repair in four to six hours using a concrete maturity meter to determine opening strength. Literature research was performed to improve current four hour opening pavement repair specifications. Material suppliers, contractors and a utility company were consulted on their mixes used. The availability/cost of Type III cement and cold-weather placement was of major concern. The evaluation of contractor, state and county pavement repair mixes, using Type I/II and III cements were tested at the time of placement for concrete temperature, entrained air, and workability. Maturity curves for some common mix designs were constructed to determine the pavement repair’s compressive strength at time of opening. A table of opening compressive strengths based on pavement repair thickness and repair length were adopted. Research concluded that at the time of placement a minimum concrete temperature of 80 Fahrenheit (27 Celsius) is critical in strength gain. The use of non-chloride calcium nitrite-based accelerating and polycarboxylate-based high-range water reducing admixture types were determined and dosages were estimated using locally available aggregate. Specifications were developed to encourage material supplier development of economical ready-mix concrete with Type I/II Portland cement. A procedure was also developed to apply the maturity method to mix design performance and verify the pavement repair’s opening strength is met in four to six hours.
  Authors: Holesinger, Richard E.
  Authors: Holesinger, Richard E.
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 237
  Paper Number: 13-0139
  Practice-Ready: Yes
• Transit Impact Fee: Enabling Statutes and Equity Concerns
  Abstract: This paper reviews four transit impact fee programs in use across the USA to examine the robustness of state and local level enabling statutes, and the strategies used to minimize the fee’s horizontal and vertical inequities. The paper finds that although impact fees are primarily used to fund capital expenses nation-wide, three of the four case study jurisdictions use the fee for funding capital expenses in addition to operating, maintenance and administrative expenses. Furthermore, clear language concerning the eligible uses should help provide robust legal protection if the fee is challenged in court. Finally, while the “nexus” and “rough proportionality” requirements ensure that the fee creates minimal horizontal inequities, no such legal requirements exist regarding the fee’s vertical equity impacts. This lack of legal requirement is reflected in the uneven use of vertical inequity mitigation strategies adopted by the case study jurisdictions.
  Authors: Mathur, Shishir; Smith, Adam Lee
  Authors: Mathur, Shishir; Smith, Adam Lee
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Planning and Forecasting; Policy; Public Transportation
  Session: 347
  Paper Number: 13-0997
  Practice-Ready: Yes
• Bus Accident Severity and Passenger Injury: Evidence from Denmark
  Abstract: Bus safety is a concern not only in developing countries, but also in the U.S. and Europe. In Denmark, disentangling risk factors that are positively or negatively related to bus accident severity and injury occurrence to bus passengers can contribute to promote safety as an essential principle of sustainable transit and advance the vision “every accident is one too many”. Bus accident data were retrieved from the national accident database for the period 2002-2011. A generalized ordered logit model allows analyzing bus accident severity and a logistic regression enables examining occurrence of injury to bus passengers.Bus accident severity is positively related to (i) the involvement of vulnerable road users, (ii) high speed limits, (iii) night hours, (iv) elderly drivers of the third party involved, and (v) bus drivers and other drivers crossing in yellow or red light. Occurrence of injury to bus passengers is positively related to (i) the involvement of heavy vehicles, (ii) crossing intersections in yellow or red light, (iii) open areas, (iv) high speed limits, and (v) slippery road surface. The findings of the current study provide a comprehensive picture of the bus safety situation in Denmark and suggest the necessity of further research into bus drivers’ attitudes and perceptions of risks and road users’ perceptions of bus operations. Moreover, these findings suggest the need for further training into bus drivers’ hazard recognition skills and infrastructural solutions to forgive possible driving errors.
  Authors: Prato, Carlo Giacomo; Kaplan, Sigal
  Authors: Prato, Carlo Giacomo; Kaplan, Sigal
  Year: 2013
  Document Type: Paper
  Subject: Motor Carriers; Safety and Human Factors
  Session: 673
  Paper Number: 13-1818
  Practice-Ready: Yes
• Scenario-Based Climate Change Risk Analysis for Transportation Infrastructure Using GIS
  Abstract: The potential impacts of climate change on transportation infrastructure have been receiving attention in recent years. Risk analysis using Geographic Information System (GIS) is an especially useful and increasingly common approach to investigating the potential impacts of climate change on infrastructure. This is because climate change effects are likely to occur in conjunction with other, geographic specific, impacts such as storm surge and traffic operations, whose vulnerability can be most effectively quantified using these GIS-based tools. To demonstrate the efficacy of these tools, this paper presents a scenario-based risk analysis approach to investigate the impacts of climate change on transportation infrastructure in Hampton Roads, Virginia. This paper first investigates the climate change effects in the study site to develop representative climate change scenarios. Next, a GIS-based evaluation of transportation infrastructure vulnerability to sea-level rise and storm surge is formed by combining the GIS dataset with the results from the Sea, Lake and Overland Surges from Hurricanes (SLOSH) model. Last, a GIS-based risk map is generated by the proposed risk model under three developed climate change threat scenarios. The results show the City of Virginia Beach is at high risk in all climate change scenarios due to climate change events, high level of transportation activity, and density of transportation facilities. The risk map—a visualization of the risk model—can assist transportation planners and decision-makers in determining asset priority to allocate their resources with respect to emergency preparation and reaction.
  Authors: Wu, Yao-Jan; Hayat, Md. Tanveer; Clarens, Andres; Smith, Brian Lee
  Authors: Wu, Yao-Jan; Hayat, Md. Tanveer; Clarens, Andres; Smith, Brian Lee
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 503
  Paper Number: 13-1832
  Practice-Ready: Yes
• Systematic Network Design for Liner Shipping Services
  Abstract: This paper addresses a systematic design of liner shipping network. Many practical features in real-world operations are considered, which include multi-type containers, container transshipment operations, empty container repositioning, origin-to-destination transit time constraint, consistent services with the current network, and joint services with other liner shipping companies. Given a set of candidate ship routes, some of these routes must be used while the others are optional for use. Hence, a mixed-integer linear programming model is first proposed for the selection of the optional ship routes. Solving this model also gives the laden and empty container flow on the selected ship routes. Based on the results of this model, some techniques are proposed to refine the ship routes, by changing existing ship routes, designing new ship routes, and removing some ship routes. Finally, a large scale numerical test is performed, based on the global shipping network of a liner shipping company, consisting of 166 ports.
  Authors: Wang, Shuaian; Liu, Zhiyuan; Meng, Qiang
  Authors: Wang, Shuaian; Liu, Zhiyuan; Meng, Qiang
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Marine Transportation; Terminals and Facilities
  Session: 344
  Paper Number: 13-1886
  Practice-Ready: Yes
• Boosting Response Rates: Evidence from Flemish Travel Behavior Survey
  Abstract: This paper investigates the transition of the Flemish travel survey (OVG) from a household-based travel survey to a person-based travel survey. The paper examines the design features of the different OVGs, with particular attention to the resulting response rates. In addition to the sample unit, the contact and survey procedure has switched from telephone/postal to face-to-face. The most striking effect of the changed methodology is the spectacular increase in the response rates: overall response rates of the most recent OVGs were more than double that of the previous OVGs, resulting in overall response rates of 75%. In addition, the likelihood that some questionnaires were missing (e.g. diaries were retrieved, but household questionnaires were not) decreased from 7% to 3%. Furthermore, the paper shows that a person-based travel survey still can be used for travel demand modeling frameworks that incorporate (some) household interactions. Notwithstanding, some issues have been raised, such as the decreased comparability of travel figures due to the changes in the survey design. In conclusion, the inclusion of a “with whom” dimension in the trip diary is recommended, and it is advocated that policy makers should clearly outline the primary objectives for the OVG for the coming years.
  Authors: Cools, Mario
  Authors: Cools, Mario
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 223
  Paper Number: 13-1888
  Practice-Ready: Yes
• Modeling Human Behavior in Vessel Maneuver Simulation by Optimal Control and Game Theory
  Abstract: This paper presents an innovative way to model the decision making process of the bridge team of a ship. The model aims to provide methods to include human decision making in comprehensive simulation models that will be able to describe the movement of vessels including hydrodynamic effects, external effects due to wind, current and waves, waterway geometry and the interaction with other vessels. In the paper, we use a simple model to describe the vessels dynamics and the impact of the control decisions on these dynamics, although generalization to more comprehensive maneuver models are straightforward. Based on a set of behavioral assumptions, the mathematical modeling framework is presented. The model is described as a differential game, where the bridge team is assumed to react on the expected behavior of other vessels. Different behavioral strategies (risk prone, risk average, risk neutral), lead to different models, which are described in the paper. By means of some simple examples, the workings of the model is illustrated. The results are plausible and clearly show the potential of the approach. The paper ends with some directions for future development.
  Authors: Hoogendoorn, Serge; Daamen, Winnie; Shu, Yaqing; Ligteringen, Han
  Authors: Hoogendoorn, Serge; Daamen, Winnie; Shu, Yaqing; Ligteringen, Han
  Year: 2013
  Document Type: Paper
  Subject: Marine Transportation; Pipelines; Safety and Human Factors
  Session: 637
  Paper Number: 13-1896
  Practice-Ready: Yes
• Moisture-Sensitive and Stress-Dependent Behavior of Pavement Unbound Materials from In Situ Falling-Weight Deflectometer Tests
  Abstract: In an instrumented flexible pavement with subsurface drainage system, a field study was performed to investigate the influence of water on the response of the pavement structure. The drainage system of the structure was clogged during a three month period, allowing the water table to rise and the structure to undergo high moisture conditions. Thereafter the drainage was reopened allowing the structure to approach its previous hydrological equilibrium state. Along with subsurface groundwater level and moisture content monitoring, the structural response of the pavement was studied by conducting frequent Falling Weight Deflectometer measurements with multilevel loads. The stress sensitivity of the unbound layers and the influence of moisture on their stiffness were studied using the data with an effort to determine the unbound materials nonlinear parameters through a backcalculation algorithm. The study showed that the response of the pavement moisture content to changes in drainage system condition was very fast. The rise in the groundwater level significantly affected the overall stiffness of the pavement structure and the backcalculated stiffness of the unbound layers decreased as their moisture content increased. It was further observed that the unbound layers exhibited stress dependent behavior to multilevel loads. The granular layer showed stress hardening behavior but the subgrade showed stress softening response in unsaturated condition and stress independent behavior in saturated state. Backcalculation of the unbound nonlinear parameters according to the universal extended k ? model revealed that the k1 parameter decreased with increasing moisture content for both the unbound granular layer as well as unsaturated fine grained subgrade material.
  Authors: Salour, Farhad; Erlingsson, Sigurdur
  Authors: Salour, Farhad; Erlingsson, Sigurdur
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials; Pavements
  Session: 293
  Paper Number: 13-1936
  Practice-Ready: Yes
• Experimental Evaluation of Shear Resistance of Improved Steel-Asphalt Interfaces
  Abstract: Although steel orthotropic deck is currently the most widely adopted solution for long-span bridges, the poor adhesion to the upper asphalt layers still represents a serious problem with a not clear solution. In recent decades many techniques, which involve the use of special bituminous bonding coats, reinforced asphalt membranes, net-reinforced steel deck surfaces or epoxy asphalt binders, have been applied, with varying results, to improve the level of adhesion of the asphalt pavement to the steel surface. In this experimental study two of such techniques were adopted in order to investigate the shear resistance of steel-asphalt pavement systems. The first technique uses epoxy asphalt both as a bonding coat and as a binder of the upper asphalt layer while the second technique concerns the use of a reinforced asphalt membrane that is applied on the steel deck before overlaying with conventional HMA.The ASTRA shear test device was used in order to evaluate the shear resistance of different types of HMA-steel interfaces and to investigate the effects of temperature and normal stress. The results have been compared with the shear properties of bitumen-coated interfaces, studied in a previous research. The results showed that epoxy asphalt guarantees high performance regardless of the test temperature. On the other hand, the shear resistance of the system with the asphalt membrane is lower than with the epoxy asphalt, although it is higher than the resistance of bitumen-coated interfaces at high temperatures.
  Authors: Bocci, Edoardo; Canestrari, Francesco
  Authors: Bocci, Edoardo; Canestrari, Francesco
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Materials
  Session: 651
  Paper Number: 13-1938
  Practice-Ready: Yes
• Reducing Specimen Size of Concrete Flexural Strength Test for Safety and Ease of Handling
  Abstract: This study examines the feasibility of using smaller size concrete beam specimens for conducting flexural strength of concrete, using simple beam with third-point loading, according to AASHTO T97 procedure. A total of 22 mixtures, containing four different coarse aggregates (limestone, diabase, gravel and granite) with maximum size varying from ¾ in to 1.5 inch, were prepared. A total of 132 4x4x14 inch specimens and 132 6x6x21 inch standard specimens size were tested. The 4x4 inch specimens yielded higher flexural strengths, as expected from the literature review. Analysis of the flexural strength test data revealed a very good correlation between the smaller and standard size beams. A model is proposed to convert the flexural strength of the small size specimen to flexural strength of the standard size specimen.
  Authors: Ardani, Ahmad Allen; Tanesi, Jussara; Leavitt, John
  Authors: Ardani, Ahmad Allen; Tanesi, Jussara; Leavitt, John
  Year: 2013
  Document Type: Paper
  Subject: Construction; Materials; Pavements
  Session: 427
  Paper Number: 13-1986
  Practice-Ready: Yes
• Isothermal Calorimetry as a Tool to Evaluate Early-Age Performance of Fly-Ash Mixtures
  Abstract: This paper documents the use of an isothermal calorimeter as scanning tool to evaluate early age behavior of high volume fly ash (HVFA) mixtures. A series of paste and mortar mixtures containing different fly ashes (one Class C fly ash and two Class F fly ashes) with replacement levels ranging from 20% to 60%, with high and low alkali cement were evaluated. Materials testing included ASTM C109, compressive strength of mortar cubes at different ages; ASTM C1437, flow; ASTM C403, time of setting and ASTM C1679, isothermal calorimetry. In most cases, for the same water-binder ratio (0.40) and replacement level, Class C fly ash mixtures exhibited higher strength but delayed setting when compared with Class F fly ash mixtures. Isothermal calorimetry proved to be a good scanning tool for prediction of setting time, early age compressive strength and identifying materials incompatibility.
  Authors: Tanesi, Jussara; Ardani, Ahmad Allen
  Authors: Tanesi, Jussara; Ardani, Ahmad Allen
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 286
  Paper Number: 13-1987
  Practice-Ready: Yes
• Geographic Scalability and Supply Chain Elasticity of a Structural Commodity Generation Model Using Public Data
  Abstract: Freight forecasting models are data intensive and require many explanatory variables to be accurate. One problem, particularly in the United States, is that public data sources are mostly at highly aggregate geographic levels, while models with more disaggregate geographic levels are required for regional freight transportation planning. Second, supply chain effects are often ignored or modeled with economic input-output models which lack explanatory power. This study addresses these challenges by considering a structural equation modeling approach, which is not confined to a specific spatial structure as spatial regression models would be, and allows for correlations between commodities. A FAF-based structural commodity generation model is specified and estimated and shown to provide a better fit to the data than independent regression models for each commodity. Three features of the model are discussed: indirect effects, supply chain elasticity, and intrazonal supply-demand interactions. A validation of the geographic scalability of the model is conducted using data imputed with a goal programming method.
  Authors: Ranaiefar, Fatemeh; Chow, Joseph Y. J.; Rodriguez-Roman, Daniel; Veiga de Camargo, Pedro; Ritchie, Stephen G.
  Authors: Ranaiefar, Fatemeh; Chow, Joseph Y. J.; Rodriguez-Roman, Daniel; Veiga de Camargo, Pedro; Ritchie, Stephen G.
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 268
  Paper Number: 13-1962
  Practice-Ready: Yes
• Remote Sensing of Weather and Road Surface Conditions: Is Technology Mature for Reliable ITS Applications?
  Abstract: Advances in road weather sensing technologies have made non-invasive road weather sensors a valuable component in many Intelligent Transportation Systems (ITS) applications. The current study presents an investigation into the reliability of using one of the aforementioned sensors for a proposed weather-responsive variable speed limit system. The Vaisala surface state and temperature sensors (DSC-111 and DST-111) were selected for the proposed application. The sensors’ ability to provide accurate and reliable data was tested under various conditions in a controlled laboratory environment. Specifically, four outputs of interest from the sensors were tested in this investigation; surface state, snow and ice depth, water depth and grip level. Testing results showed that the sensors determined the surface state (dry, moist, wet, snowy and icy) accurately and reliably. The sensor’s snow depth readings were found to be inaccurate, while the sensor’s ice depth measurements were found to be relatively close to the actual depths. In regards to water depth, only a limited number of readings were close to the actual depths while other readings were highly inaccurate. In an effort to test the potential of the sensor in providing reliable inputs to the proposed ITS application, a calibration was conducted for the sensor water depth measurements using various water depths and sensor installation angles. Calibration results showed that the water depth could be accurately estimated using the calibrated sensor measurements regardless of water depth or sensor installation angle. Sensor estimates of grip level were found highly correlated to the coefficient of static friction for the conditions considered in this study. Keywords: weather sensor, snow, friction, calibration, ITS
  Authors: Ewan, Levi; Al-Kaisy, Ahmed; Veneziano, David A.
  Authors: Ewan, Levi; Al-Kaisy, Ahmed; Veneziano, David A.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Safety and Human Factors
  Session: 251
  Paper Number: 13-1997
  Practice-Ready: Yes
• Dispatching Strategies for Taxi-Customer Searching Problem in Booking Taxi Service
  Abstract: Automatic taxi dispatching has been widely used in many large cities worldwide, in which customers can book taxis through phones or mobile devices. Two types of bookings are commonly known: one is the Current Booking (CBK), the customer makes a booking call for a taxi that can reach him/her as early as possible; another is the Advance Booking (ABK), the customer makes a booking call and indicates the pickup time which is normally in half an hour or later. In this paper, taking the taxi by making either CBK or ABK is defined as the Booking Taxi Service (BTS) while taking the taxi by either waiting at taxi stand or hailing on the street is defined as the Non-Booking Taxi Service (NBTS). In order to evaluate different dispatching strategies, a Taxi-Customer Searching Problem (TCSP) is formulated in this paper in which both BTS and NBTS are considered, and different dispatching strategies are evaluated and compared. The microscopic traffic simulation is adopted as the approach for modeling and analysis of the TCSP. A sensitivity analysis by varying the booking demand is conducted based on the simulation, and the simulation results show that the Advance Booking Chain Dispatching Strategy (ABC-DS) can give better operational performance in certain demand levels which may have the potential to attract more customers to take the taxi by booking in advance. Moreover, these results can also provide strategic implications for the taxi operators.
  Authors: Lee, Der-Horng; Wu, Xian
  Authors: Lee, Der-Horng; Wu, Xian
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 354
  Paper Number: 13-1975
  Practice-Ready: Yes
• Limited Information Sharing Strategy for the Taxi-Customer Searching Problem in Non-Booking Taxi Service
  Abstract: One of the issues existed in the current taxi service is the imbalance between supply and demand. In response to this issue, the automatic taxi dispatching approach in which customers can book taxis through phones or mobile devices is widely used in many large cities worldwide. However, the utilization of this approach is not satisfied, since most customers still prefer the Non-Booking Taxi Service (NBTS) that taking the taxi by either waiting at taxi stand or hailing on the street. One important reason for this phenomenon is that the customer takes lower risk in NBTS: they are free from complicated booking procedures and have no commitment to any yet-arrived taxis. In order to facilitate the taxi-customer matching process in NBTS, this paper has proposed a novel control strategy namely the Limited Information Sharing Strategy (LISS) for the Taxi-Customer Searching Problem (TCSP) in NBTS, in which both the taxi and the customer are equipped with mobile devices that can communicate with each other within limited searching ranges. The proposed LISS is based on the game-theoretical formulation in which a learning algorithm is developed to find the pure Nash-Equilibrium (NE). A microscopic traffic simulation model is developed for the evaluation of the LISS. The simulation results show that the proposed LISS is an effective control strategy when taxi supply is low, and it will not increase the risk of taxi in terms of losing the total occupied time.
  Authors: Lee, Der-Horng; Wu, Xian; Sun, Lijun
  Authors: Lee, Der-Horng; Wu, Xian; Sun, Lijun
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 393
  Paper Number: 13-1981
  Practice-Ready: Yes
• Structural Pattern Effects on Engineering Behavior of Hexagonal Wire Mesh Gabion Panels
  Abstract: Three half-turn and four half-turn hexagonal wire mesh panels were built for tensile and punch tests with and without one center cut wire mesh panel. The study results indicated that the ultimate tensile strength or punch resistance for three half-turn and four half-turn hexagonal wire mesh panels without any cut within were similar. However, the four half-turn hexagonal wire panels showed better tensile and punch resistance after one wire broke at the panel center. This implied that the presence of broken wires within the four half-turn hexagonal wire mesh showed no significant influence on the panel¡¦s tensile strength and punch resistance. Four half-turn hexagonal wire mesh is a better structural pattern than that the three half-turn hexagonal wire mesh for slope stability and river bank protection applications.
  Authors: Hsieh, Chiwan Wayne; Chang, CheWei; Liu, In-Wei; Liu, Ren Sheng
  Authors: Hsieh, Chiwan Wayne; Chang, CheWei; Liu, In-Wei; Liu, Ren Sheng
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology
  Session: 243
  Paper Number: 13-1982
  Practice-Ready: Yes
• Non-coverage Errors in Travel Surveys Due to Mobile Phone Only Households
  Abstract: National and regional household travel surveys have conventionally sampled landline telephone households through list-assisted random digit dialing. However, a recent increase in “mobile phone only” households results in either non-coverage or under-coverage of a growing segment of the population. This can potentially cause a substantial bias in the representativeness of travel behavior toward the target population. To cover mobile phone only households, an address-based sampling method is of interest. This study explores whether the characteristics and travel behavior of mobile phone only households differ from those of households with landline telephones. In addition, this study quantifies the extent of non-coverage errors in the surveys in terms of the respondents’ travel behavior. Along with census data, the mobile phone only sample (N=2,988) was compared with the landline telephone sample (N=7,774) drawn from the 2008 National Capitol Region Household Travel Survey. Results show that the mobile phone only sample consists of relatively more single-person households, younger individuals, and Blacks/Asians/Hispanics, which are generally identified as hard-to-reach groups. Statistical models were developed to examine differences in travel behavior (e.g., trip-making), suggesting that the mobile phone only households make more transit (27%) and walking (18%) trips. This is partly due to the spatial distribution of the residential locations between the two groups, which are found to be statistically significant. Regarding non-coverage errors, results show that the inclusion of the mobile phone only households can reduce the errors, especially for transit and walking travel behaviors. The implications for travel survey methods are further discussed.
  Authors: Son, Sanghoon; Khattak, Asad J.; Kim, Nak-Kyeong
  Authors: Son, Sanghoon; Khattak, Asad J.; Kim, Nak-Kyeong
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 765
  Paper Number: 13-2028
  Practice-Ready: Yes
• Economics Behind Electric Vehicles: Analysis from the Private User’s Perspective in France
  Abstract: A holistic total costs of ownership (TCO) approach compares electric with conventional vehicles (EVs with CVs). The impact of policy measures and market trends throughout time is studied; the inclusion of vehicle user- and vehicle usage-characteristics in the set-up calculation model ensures a disaggregate approach that allows for detailed EV-demand projections in future studies. Each vehicle technology accommodated in the set-up TCO calculation model is represented by specific vehicle models that are currently available on the French market. Their characteristics and costs serve as the basis of TCO calculations. Results show that the underlying plug-in hybrid electric vehicle (PHEV) model is, from a TCO perspective, not competitive with any other electric or conventional vehicle underlying the analysis. This is valid for all developed scenarios and realistic vehicle usage patterns. Assuming that the here selected vehicle models well represent the vehicle technologies in question, it can be expected that the future demand of PHEVs having long electric ranges will fully rely on the goodwill of selected users. The most competitive electric EV type appears to be the battery electric vehicle with battery hire. The development of ‘financially reasoned’ demand for this vehicle and business model seems therefore realistic. Generally, compact electric vehicles that are to replace petrol vehicles appear to be more competitive with their conventional counterparts than sedan vehicles that are to replace diesel-driven vehicles. All results refer to current and forecasted French framework conditions and are subject to various necessary assumptions.
  Authors: Windisch, Elisabeth
  Authors: Windisch, Elisabeth
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 503
  Paper Number: 13-2019
  Practice-Ready: Yes
• Feasibility Study for Converting High-Occupancy-Vehicle Lanes to Managed Lanes in Dallas, Texas
  Abstract: Excess capacity in HOV lanes during peak periods can be made available to other types of vehicles, including single occupancy vehicles (SOV) for a price (toll). Such dual use lanes are typically referred to as Managed Lanes or HOT Lanes. This study utilizes a methodology for equilibrating the demand across the managed and general-purpose lanes to examine the feasibility of such conversions under various toll price strategies. The AM and PM peak period demands are used as the basis for the study. The pricing strategies include charging SOV vehicles at $0.10/mile, $0.25/mile, or $0.50/mile while having no charge for HOVs. For each of the three SOV pricing strategies, quantitative estimates of toll revenues and emissions on managed and general purpose lanes are obtained. Comparisons are made to the current practice of not allowing SOVs in HOV lanes and all HOVs to using the lanes free of charge.
  Authors: Ardekani, Siamak A.; Olyai, Koorosh
  Authors: Ardekani, Siamak A.; Olyai, Koorosh
  Year: 2013
  Document Type: Paper
  Subject: Finance; Operations and Traffic Management; Policy
  Session: 294
  Paper Number: 13-2022
  Practice-Ready: Yes
• Development and Implementation of a Network-Level Pavement Optimization Model for Ohio Department of Transportation
  Abstract: Optimal use of pavement maintenance and rehabilitation budget is essential in a constrained budget environment such as now. This paper presents the development and implementation of a network-level optimization model within a pavement management information system (PMIS) for the Ohio Department of Transportation (ODOT). Future pavement condition is predicted based on historical pavement data using a Markov transition probability model. Such transition probabilities are updated automatically when new condition data become available each year. The network-level optimization model integrates a linear programming model and the Markov transition probability model. This optimization tool is capable of (1) calculating the minimum budget required to achieve a desired level of pavement network condition, (2) maximizing the improvements of pavement network condition with a given amount of budget, and (3) determining the corresponding optimal treatment policy and budget allocations. It can be used by highway agencies as a decision support tool for network-level pavement management decisions.
  Authors: Wang, Shuo; Chou, Eddie Yein-Juin; Williams, Andrew
  Authors: Wang, Shuo; Chou, Eddie Yein-Juin; Williams, Andrew
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 479
  Paper Number: 13-2035
  Practice-Ready: Yes
• Leveraging Project- and Scenario-Level Performance Assessment to Achieve Sustainability Goals of Plan Bay Area
  Abstract: Senate Bill 375 requires metropolitan planning organizations in California to develop an integrated transportation, land use, and housing plan – known as a Sustainable Communities Strategy. This plan must be targeted to reduce greenhouse gas emissions from cars and light-duty trucks. To meet these requirements, the San Francisco Bay Area Metropolitan Transportation Commission (MTC) and the Association of Bay Area Governments (ABAG) are developing Plan Bay Area, which integrates the Sustainable Communities Strategy with the upcoming cycle of the Regional Transportation Plan. In order to achieve the plan’s sustainability goals, San Francisco Bay Area regional agencies are relying on a performance-based approach, targeting key issues such as strengthening the region’s economy, promoting equity, and enhancing the environment. This approach focuses on measurable outcomes to help understand how land use strategies and potential transportation investments could advance the region’s goals. Following the adoption of a set of ten quantitative performance targets, transportation projects and scenarios were evaluated based on their level of support for these targets. A benefit-cost assessment was also leveraged to assess the cost-effectiveness of regionally-significant transportation projects and scenarios.This paper will present Plan Bay Area’s performance assessment methodology and discuss both its abilities and limitations in capturing impacts of infrastructure investments. The assessment approach will be examined both for individual transportation projects and for integrated regional transportation and land use scenarios.
  Authors: Vautin, David; Klein, Lisa; Co, Sean; Jeannotte, Krista; Sallman, Doug
  Authors: Vautin, David; Klein, Lisa; Co, Sean; Jeannotte, Krista; Sallman, Doug
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Policy; MAP-21
  Session: 355
  Paper Number: 13-2058
  Practice-Ready: Yes
• State of the Practice on Use of Intelligent Transportation Systems at U.S.-Mexico Land Border Crossings
  Abstract: A research project was conducted to perform a border-wide assessment of the use of Intelligent Transportation Systems (ITS) technologies and operational concepts at and near U.S. international land border-crossings. The work focused on tolling, traffic management and operations, and safety. The specific objectives of this project were to research, assess and document how ITS technologies can be used in areas of (1) toll collection and management in border regions, identifying technologies used, system components, and any special data sharing arrangements between the United States and its two bordering neighbors; (2) transportation operations and traffic management in U.S./Mexico border regions; (3) transportation safety policy and operations; (4) traffic management, traffic operation and traffic enforcement on tolled roads/tolled border-crossing roads; and (5) archiving toll and traffic management data. In the interest of brevity, this paper discusses results of the study pertaining to the state-of-the-practice on use of ITS on the U.S.-Mexico border only.
  Authors: Rajbhandari, Rajat; Villa, Juan Carlos; Macias, Roberto; Tate, William H.
  Authors: Rajbhandari, Rajat; Villa, Juan Carlos; Macias, Roberto; Tate, William H.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 434
  Paper Number: 13-2064
  Practice-Ready: Yes
• Evaluation of Roundabout Safety
  Abstract: While roundabouts are still fairly new in the U.S. and Wisconsin, their safety benefits have been studied with varied results. In this study, 24 roundabouts built in 2007 or before were analyzed for their safety performance. Three years of before and after crash data were gathered as well as geometric and traffic volume data. An empirical Bayes (EB) analysis was used to examine the safety benefits for total crashes and injury (K, A, B, C) crashes.The EB analysis was performed using the Safety Performance Functions (SPFs) from the Highway Safety Manual (HSM). Mixed results were found for total crash frequency but a significant decrease in crash severity was identified. Wisconsin roundabouts had an unbiased estimate of a 9.2 percent decrease in total crashes. National numbers similarly show decreases in total crashes. Wisconsin roundabouts showed a significant 52 percent decrease in injury crashes. Roundabouts nationwide are also experiencing a significant decrease in severe crashes.When evaluating predictors, the speed limit of the approaches did not show a significant impact on the safety of the roundabout. While multi-lane roundabouts seemed to be safer than single lane roundabouts when considering combined injury crashes, single lane roundabouts saw the largest decrease in total crashes. Two-way stop controlled (TWSC) intersection conversion to a roundabout had the highest safety benefit as compared to all-way stop controlled (AWSC) and signalized intersections.
  Authors: Qin, Xiao; Bill, Andrea R.; Chitturi, Madhav V.; Noyce, David A.
  Authors: Qin, Xiao; Bill, Andrea R.; Chitturi, Madhav V.; Noyce, David A.
  Year: 2013
  Document Type: Paper
  Subject: Design; Operations and Traffic Management; Safety and Human Factors
  Session: 542
  Paper Number: 13-2060
  Practice-Ready: Yes
• Has the Introduction of Cycle-to-Work Scheme Increased Levels of Cycling to Work in the United Kingdom?
  Abstract: Cycling is seen as a sustainable way to travel, and as a factor contributing to a more active and healthy lifestyle, and therefore is being encouraged in the UK and elsewhere. The overarching aim of this study is to establish the value of the UK Cycle to Work (tax-free) Bike scheme in encouraging people to cycle to work. Using primary data, collected from 248 scheme participants and 101 non-participants, it attempts to identify whether there was a change in travel behaviour among scheme participants and to what extent; and to evaluate if publicity and promotion of the scheme encouraged scheme participation. The study also investigates which socio-economic and other factors influence the propensity to participate in the scheme, and explores the correlation between stages of behaviour change and a person’s intention to cycle.
  Authors: Avineri, Erel; Fiona, Steven
  Authors: Avineri, Erel; Fiona, Steven
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Planning and Forecasting; Policy
  Session: 556
  Paper Number: 13-2068
  Practice-Ready: Yes
• Factors Affecting Motorcycle Conspicuity: Driving Simulator-Based Study
  Abstract: This paper investigates the effect of headlight configuration (daytime running lights, high beam and modulating headlights) and rider color (bright yellow, blue denim, and black torso and helmet) on the conspicuity of a motorcycle to younger (25 to 55 years old) and older drivers (65 and older) of a passenger vehicle in simulated urban and rural environments. To achieve this, 36 participants completed two study drives on a National Advanced Driving Simulator (NADS)-2 driving simulator. During the drives, participants were presented with six oncoming motorcycles and three leading parked motorcycles, each with a different combination of rider color and headlight configuration. Participants indicated when each motorcycle was first visible to them by pressing a button on the steering wheel of the driving simulator and detection distances from the motorcycles to the participant vehicles were recorded. The applied repeated measures analysis of variance suggested that oncoming motorcycles with modulating headlights were detected at the greatest distance compared to motorcycles with high beam or daytime running lights irrespective of the rider color. Leading motorcycles in urban environments were detected at a greater distance compared to those in rural environments. Leading motorcycles with riders having bright yellow clothing and helmet were detected at the greatest distance, followed by motorcycles with riders having blue denim and black clothing and helmet. The interaction effect among the driving environment, rider color, and age group was also found significant for the detection distance of leading motorcycles.
  Authors: Shaheed, Mohammad Saad Bin; Marshall, Dawn; Gkritza, Konstantina
  Authors: Shaheed, Mohammad Saad Bin; Marshall, Dawn; Gkritza, Konstantina
  Year: 2013
  Document Type: Paper
  Subject: Safety and Human Factors
  Session: 811
  Paper Number: 13-2096
  Practice-Ready: Yes
• Parallel Label-Correcting Algorithms for Large-Scale Static and Dynamic Transportation Networks on Laptop Personal Computers
  Abstract: A parallel implementation of the Label Correcting Algorithm (LCA) for finding shortest paths on static networks is first presented. The parallel static LCA is then extended to include time-dependent link costs. For both the static and time-dependent cases, an efficient sparse matrix storage scheme that has been frequently employed by “sparse equations solver researchers” is adopted. It can be shown that the proposed sparse storage scheme is equivalent (in terms of computer memory requirement) to the forward or reverse star representation that is often used by transportation researchers.The proposed parallel (time-dependent) LCA simply assigns each processor to handle a number of source (or destination) nodes within a network. Both real (and randomly generated), static and time-dependent transportation networks (including a network with 100,000 nodes and 349,850 links) are extensively used to evaluate the numerical efficiency (in terms of accuracy, and wall-time) of the proposed parallel LCA, using inexpensive desktop/laptop Personal Computers (PCs), and under the C#, C++, and MATLAB programming languages.Numerical results demonstrate that the proposed parallel LCA is simple and very efficient. While implementing the proposed parallel LCA in the MATLAB / C++ environments offer the reasonable / very good efficiency of around 65% / 87%, its efficiency increased to be in the remarkable range of 95.11 % (which is very close to the 100% ideal/ perfectly linear efficiency) through 167.12% (which is considered as “super-linear” performance) when implementing in the C # environment.
  Authors: Nguyen, Duc Thai; Ng, ManWo
  Authors: Nguyen, Duc Thai; Ng, ManWo
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 844
  Paper Number: 13-2103
  Practice-Ready: Yes
• Development of Estimating Tool for Transportation Project Design
  Abstract: The development of an estimating tool to assist New York State Department of Transportation (NYSDOT) managers is described. The tool was developed using Microsoft Access. It enables managers to input project characteristics and then search a data base of historical projects. The estimating tool returns the staffing levels for similar completed projects. The system was also developed to allow newly completed projects to be added to the data base and to allow for the monitoring of design hours expended for projects that are in progress. Regression analysis was also explored as a means of predicting total project design hours. With the assistance of NYSDOT experts important factors that influence required design hours were identified. Estimating tool users can make a regression prediction for the total project hours using historical projects as input data.
  Authors: Williams, Trefor P.; Parker, Neville A.; Klotz, James
  Authors: Williams, Trefor P.; Parker, Neville A.; Klotz, James
  Year: 2013
  Document Type: Paper
  Subject: Construction
  Session: 238
  Paper Number: 13-2111
  Practice-Ready: Yes
• Past Experience with Green Noise Barriers
  Abstract: A green noise barrier is a noise barrier that utilizes soil and vegetation to mitigate traffic noise. This paper provides an overview of available green noise barriers along with a summary of their advantages and limitations. It addition, it presents case studies documenting the past experience of several highway agencies with green noise barriers. This information was obtained form a questionnaire that was sent out to more than three hundred national and international experts in traffic noise analysis and abatement. This paper also provides a series of conclusions and recommendations regarding the implementation of green noise barriers.
  Authors: Abbas, Ala Rebhi; Frankhouser, Andrew; Cubick, Karel; Liang, Robert; Cardina, John
  Authors: Abbas, Ala Rebhi; Frankhouser, Andrew; Cubick, Karel; Liang, Robert; Cardina, John
  Year: 2013
  Document Type: Paper
  Subject: Environment
  Session: ADC40
  Paper Number: 13-2154
  Practice-Ready: Yes
• Estimating Statewide Benefits of Winter Maintenance Operations
  Abstract: Winter highway maintenance activities offer direct and indirect benefits to the public. However, the cost of such activities is such a major outlay that it demands close scrutiny. There is a need to better understand and quantitatively estimate the benefits of winter road maintenance. Therefore, the work discussed in this paper was undertaken to quantitatively assess the benefits of winter highway operations at the state level. Methodologies were developed for estimating the major benefits of winter maintenance, including safety improvements, travel time savings and fuel savings. A Minnesota case was used to demonstrate the methodologies and quantify those benefits. Results of the case study showed that the benefits of winter highway maintenance by the Minnesota Department of Transportation to be $227 million per winter season, with $168 million of safety benefits, $11 million of mobility benefits, and $48 million of fuel savings. The benefit-cost ratio of winter highway operations in Minnesota was 6.2, in which material costs were taken into account.
  Authors: Ye, Zhirui; Veneziano, David A.; Shi, Xianming
  Authors: Ye, Zhirui; Veneziano, David A.; Shi, Xianming
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Safety and Human Factors
  Session: 251
  Paper Number: 13-2148
  Practice-Ready: Yes
• How Service Learning is Integrated with Transportation Curriculum to Support Career and Education Development
  Abstract: The Transportation, Logistics and Cargo Security (TLCS) Program at Anne Arundel Community College (AACC) was created to provide new students and incumbent workers with a broad understanding of the transportation industry. The success of the program has led to continued educational offerings for students interested in industry credentials. The program focuses on professional education and ties these concepts to current workforce needs, career awareness, and career preparation through many methods. Delivered content provides career opportunities through professionally created program videos, classroom content, guest speakers, and local field trips. Students learn industry skills and knowledge through the participation in service learning and engaged learning projects. Service-learning, which provides applied learning experiences by linking community service, curriculum, and reflection are effective educational tools used in the TLCS Program. Active and engaged learning activities are also used to provide students hands on experiences to tie classroom material to workforce activities. TLCS program students apply supply chain and transportation concepts though participating in specialized activities. This example of utilizing active learning activities supports growth in industry education and career knowledge.
  Authors: Snow, Kipp
  Authors: Snow, Kipp
  Year: 2013
  Document Type: Paper
  Subject: Education and Training
  Session: 396
  Paper Number: 13-2140
  Practice-Ready: Yes
• I-35W South Mnpass High-Occupancy-Toll Lanes
  Abstract: The I-35W South MnPASS high-occupancy toll (HOT) lanes in the Minneapolis-St. Paul metropolitan area were a major component of the Minnesota Urban Partnership Agreement (UPA) funded by the U.S. Department of Transportation (U.S. DOT). The use of the I-35W South HOT lanes is examined in this paper. Information on the number of MnPASS accounts, daily and monthly trips, monthly revenues, average tolls, and maximum tolls is presented. Changes in trip-time savings and trip-time reliability are also discussed. The results from a 2012 survey of I-35W MnPASS customers are summarized. This paper highlights key elements of the national evaluation of the Minnesota UPA related to the I-35W South HOT lanes. The national evaluation is sponsored by the U.S. DOT and conducted by a research team headed by Battelle Memorial Institute. As discussed in this paper, the I-35W South HOT lanes have attracted new MnPASS customers, while maintaining the travel-time savings and trip-time reliability for buses and carpools.
  Authors: Turnbull, Katherine F.; Buckeye, Kenneth; Thompson, Nick
  Authors: Turnbull, Katherine F.; Buckeye, Kenneth; Thompson, Nick
  Year: 2013
  Document Type: Paper
  Subject: Finance; Operations and Traffic Management; Policy
  Session: 294
  Paper Number: 13-2146
  Practice-Ready: Yes
• Comparative Analyses of Stated Behavioral Responses to Off-Hour Delivery Policies
  Abstract: The analyses reported in this paper show the benefits of using behavioral research to understand the stated behavioral responses of different economic agents (receivers and carriers) to off-hour delivery (OHD) policies in two major business areas in New York City, i.e., Manhattan and Brooklyn. These policies include a tax deduction and shipping discounts for receivers, and customer requests combined with toll discounts, or financial rewards for carriers. Given the relatively small amount of research conducted in stated and revealed behavioral responses, the results for Manhattan and Brooklyn provide insights for the operations of receiver and carrier companies in areas of similar characteristics.
  Authors: Jaller, Miguel Angel; Holguín-Veras, Jose
  Authors: Jaller, Miguel Angel; Holguín-Veras, Jose
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 407
  Paper Number: 13-2149
  Practice-Ready: Yes
• Evaluation of a Heavy Polymer-Modified Binder Through Accelerated Pavement Testing
  Abstract: In 2001, the Florida Department of Transportation (FDOT) conducted an experimental study to assess the effect of polymer modified PG76-22 asphalt binder on rutting resistance of Superpave mixtures through Accelerated Pavement Testing (APT). The success of this study led to the use of PG76-22 binder on the final structural course for traffic level D (10 to > 30 million equivalent single axle loads, or ESALs) mixtures and the top two structural courses for traffic level E (¡Ý 30 million ESALs) mixtures. At times, however, localized failures still do occur at locations with concentrated truck traffic and low speeds. In response, a follow-up APT study was conducted to evaluate the performance of a polymer-modified asphalt binder meeting PG82-22 requirements. Results of the study indicated that the use of a heavy polymer modified binder improved rutting and cracking performance of asphalt mixtures.
  Authors: Greene, James; Choubane, Bouzid; Chun, Sanghyun
  Authors: Greene, James; Choubane, Bouzid; Chun, Sanghyun
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 574
  Paper Number: 13-2150
  Practice-Ready: Yes
• Ruggedness Study of Coefficient of Thermal Expansion of Concrete Test Method AASHTO T336
  Abstract: A ruggedness study on AASHTO T336 was performed in order to evaluate the most likely factors to affect the test results. Seven factors were evaluated: time at temperature extremes, water level, position of the LVDT, number of segments, saturation criterion, specimen length and temperature of the first segment. Four laboratories participated and a total of five commercially made CTE devices from two different manufacturers were used. Two different concrete mixtures were used in this study. Based on the results obtained, saturation criterion was found to be the most significant factor. All the other factors, either were found not to have a significant impact on the tests results, have already been addressed in the most current version of the test method or, in the authors’ opinion don’t need to be addressed.
  Authors: Tanesi, Jussara; Gudimettla, Jagan M.; Crawford, Gary L.; Ardani, Ahmad Allen
  Authors: Tanesi, Jussara; Gudimettla, Jagan M.; Crawford, Gary L.; Ardani, Ahmad Allen
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-2167
  Practice-Ready: Yes
• Marine Highway Transport of Toxic Inhalation Hazard Materials
  Abstract: This paper presents highlights of research conducted under Phase 2 of NCFRP 17 North American Marine Highways in order to investigate the possibility of transporting greater volumes of chlorine and anhydrous ammonia via the marine highway system. Currently, there is no coastwise and limited inland waterway activity related to either. The researchers identified the major obstacles to development and expansion and corresponding potential courses of action. Geographical dispersion of producers and consumers works against greater waterborne volumes. Both chemicals are characterized by mature, low-growth markets. Expansion of marine services will require significant capital costs and time to set up new terminals. There is great concern over the condition of the current system of locks and dams. Marine carriers, absent any action by the federal government, face the same economic ramifications from risk of catastrophic accidents faced by rail carriers, necessitating the establishment of a new risk paradigm. The federal government could provide initial funds and expedite the permitting process to allow new marine highway ventures to develop more rapidly. It could also identify and assist potential new import points for both chemicals into the U.S. Finally, the federal government must indicate its commitment to maintain the current inland waterway system. However, there are no measures that can overcome the geographical dispersion of producers and users, the lack of density in any given corridor, and the fact that the markets are mature. Therefore, significant expansion of TIH materials transportation via marine highways is not anticipated.
  Authors: Protopapas, Annie; Kruse, Carl James; Olson, Leslie; Hutson, Nathan; Donelan, Mike
  Authors: Protopapas, Annie; Kruse, Carl James; Olson, Leslie; Hutson, Nathan; Donelan, Mike
  Year: 2013
  Document Type: Paper
  Subject: Environment; Marine Transportation; Terminals and Facilities
  Session: 217
  Paper Number: 13-2205
  Practice-Ready: Yes
• Modeling and Load Rating of Two Bridges Designed with AASHTO and Florida I-Beam Girders
  Abstract: Florida I-Beam (FIB) girders provide a number of advantages such as higher load carrying capacity, more efficient fabrication, safer construction, increased lateral stiffness, larger vertical clearance and reduction in the overall cost of bridges. A comparative study incorporating two bridges, one with AASHTO Type III and the other with new Florida I-Beam (FIB) girders is presented. The first bridge is a 3 span bridge designed with 6 AASHTO Type III girders. The second bridge has the same length, width and girder depth; however, it has 4 FIB girders. Both bridges are analyzed using the conventional AASHTO LRFD girder line analysis method and also with a more sophisticated finite element method using a commercial software. The details of the FE model are also presented with the critical considerations of link elements, boundary conditions, pre-stressing tendons. Based on the FE model results, it is shown that it is possible to expect 20% higher live load capacity for interior girders and 40% higher live load capacity for exterior girders using FIB-45 girders compared to AASHTO Type III girders, while also reducing the cost by about 24%.
  Authors: Catbas, F. Necati; Darwash, Haider; Fadul, Manar
  Authors: Catbas, F. Necati; Darwash, Haider; Fadul, Manar
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Safety and Human Factors
  Session: 703
  Paper Number: 13-2212
  Practice-Ready: Yes
• Modeling Reservation-Based Autonomous Intersection Control in VISSIM
  Abstract: Autonomous vehicles are attracting more and more attention as a promising approach to improve both highway safety and efficiency. Most previous studies on autonomous intersection management relied heavily on custom-built simulation tools to implement and evaluate their control algorithms. The use of the non-standard simulation platforms makes comparison between different systems almost impossible. Additionally, without support from standard simulation platforms, reliable and trustworthy simulation results are hard to obtain. In this context, this paper explores a way to model autonomous intersections using VISSIM, a standard microscopic simulation platform. Specifically, a reservation-based intersection control system, named Autonomous Control of Urban TrAffic (ACUTA), was introduced and implemented in VISSIM using VISSIM’s External Driver Model. The operational and safety performances of ACUTA were evaluated using the easy-to-use evaluation tools of VISSIM. Compared with the optimized signalized control, significantly reduced delays were resulted from ACUTA along with a higher intersection capacity and lower volume-to-capacity (v/c) ratios under various traffic demand conditions. The safety performance of ACUTA was evaluated using the Surrogate Safety Measure Model, and presented few conflicts among vehicles within the intersection. Moreover, the key steps and elements for implementing ACUTA in VISSIM are introduced in the paper, which can be useful for other researchers and practitioners in implementing their autonomous intersection control algorithms in a standard simulation platform. By using a standard simulation platform, performance of different autonomous intersection control algorithms can be eventually compared.
  Authors: Li, Zhixia; Chitturi, Madhav V.; Zheng, Dongxi; Bill, Andrea R.; Noyce, David A.
  Authors: Li, Zhixia; Chitturi, Madhav V.; Zheng, Dongxi; Bill, Andrea R.; Noyce, David A.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 674
  Paper Number: 13-2186
  Practice-Ready: Yes
• Modal Comparison of Domestic Freight Transportation Effects on the General Public
  Abstract: This study used data from 2001-2009 to update the 2009 modal comparison study conducted by the Texas Transportation Institute, which used data from 2001-2005. The objective was to develop performance measures in terms of rates per ton-mile in order to facilitate multimodal comparisons between inland towing, rail, and truck in six topical areas: cargo capacity, traffic congestion, energy efficiency, air quality, safety, and infrastructure. This study considered a snapshot in time in order to focus on several vital issues. Every effort was made to use credible, publicly available, and independently verifiable data from federal, industry or academic sources. The scope of the study and several data limitations necessitated the use of assumptions based on sound engineering principles and the development of innovative methods in order to arrive at plausible results and fulfill the study’s unconventional objectives. The study concluded that waterborne transportation continues to compare favorably to the rail and highway modes in terms of the performance measures examined. Any waterborne freight diversion to either of the two modes would likely result in serious negative effects on their freight transportation operations and possible system breakdowns. Chain reaction effects would severely jeopardize the well-being of the general public and the national economy.
  Authors: Protopapas, Annie; Kruse, Carl James; Olson, Leslie
  Authors: Protopapas, Annie; Kruse, Carl James; Olson, Leslie
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Marine Transportation; Planning and Forecasting
  Session: 345
  Paper Number: 13-2200
  Practice-Ready: Yes
• Feasibility Study of Fuel Consumption Prediction Modelby Integrating Vehicle-Specific Power and Controller Area Network Bus Technology
  Abstract: With the development of automobile technology, it becomes possible to estimate the fuel consumption using the driving parameters from the Electronic Control Unit (ECU) and output the calculation results via the Controller Area Network (CAN) bus. As a result, it is feasible to design an approach for estimating the fuel consumption by integrating vehicle specific power (VSP) and CAN bus technology because of the accessibility and stability of the CAN bus. In order to determine whether the CAN-based measured data can be used to build the relationship between VSP and fuel consumption to replace the traditional fuel consumption meter, a comparison of fuel consumption data collected from ECU and the fuel consumption meter is conducted in this study. The results show that the relationship between the fuel consumption rate and VSP bin built by the CAN bus data is consistent with the one derived from the fuel consumption meter, which indicates that the CAN bus technology can be used to describe the relationship between vehicle activities and fuel consumption rates for light-duty vehicles. In addition, a comparison of CAN-based measured data with VSP-based predicted data shows that the prediction approach that integrates VSP and CAN bus technology need an aggregation level of 60s or longer, which thus can be used to estimate a long-period of fuel consumption accumulation and fuel consumption factor for various travel speeds and road types.
  Authors: Wu, Yizheng; Yu, Lei; Song, Guohua; Xu, Long
  Authors: Wu, Yizheng; Yu, Lei; Song, Guohua; Xu, Long
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-2201
  Practice-Ready: Yes
• Public Perceptions and Preferences towards a VMT Fee System in Nevada
  Abstract: A number of barriers are associated with the implementation and deployment of a Vehicle Miles of Travel (VMT) system, ranging from technology issues to public acceptance. Technologically related barriers are easier to address compared to publicly related barriers. In addition, addressing technological barriers requires explicit consideration of the public attitudes and preferences towards various technological options. This paper studies public perceptions and preferences towards a VMT system in Nevada. A survey questionnaire was developed to capture these perception and preferences. A series of discrete choice models – including ordered, probit, and logit models – were tested to determine the best model to use for evaluating the results of the survey. Multinomial logit models provided the best explanatory power. Modeling assumptions were tested to ensure adequate results. The model provided a number of interesting insights about public perceptions and preferences regarding the VMT system. Based on these insights, some policy recommendations are provided.
  Authors: Nordland, Andrew; Paz, Alexander; Khan, Alauddin
  Authors: Nordland, Andrew; Paz, Alexander; Khan, Alauddin
  Year: 2013
  Document Type: Paper
  Subject: Economics; Finance
  Session: 387
  Paper Number: 13-2215
  Practice-Ready: Yes
• Overcoming an Environmental Surprise with Innovative, Fast-Track Technology: Case History Along I-69 Through Tennessee
  Abstract: As Tennessee DOT was finalizing the route of the future I-69 through northwest Tennessee, a previously unknown, unregulated landfill was discovered directly beneath the proposed route near its juncture with a continuing segment into Kentucky. Tennessee DOT, cooperating with Tennessee Department of Environment and Conservation, implemented a rapid-response, technology-driven strategy to assess the costs and liabilities of crossing the landfill versus avoiding it. Following a concerted site-history investigation, an electromagnetic geophysical survey mapped the landfill boundaries, established the area of fill, and identified areas of waste segregation within the fill. A concurrent soil gas survey showed only isolated patterns of volatile organic compounds, often a driver for environmental mitigation costs. These results optimized locations for subsurface drilling, which deployed the waste-minimizing sonic technique. Drilling established the depth of fill across the site, which, combined with the geophysical delineation of lateral extent, yielded a waste-volume estimate of 65,000 m3 (85,000 yd3) within the proposed I-69 footprint. Chemical analyses were done for subsurface sonic soil cores, surface soil samples, the contents of drums scattered across the surface, and surface water. These analyses showed relatively modest environmental risks, suggesting that if the landfill were excavated, most of the soil could be handled as nontoxic special waste. Nevertheless, considering both design-build factors and environmental issues, the cost of excavating and building through the landfill ($33.5 million) exceeded that of rerouting slightly east of the landfill ($29.5 million). The route was diverted to avoid the landfill.
  Authors: Hughes, Larry J.; Epperson, Ann; Williams, Tammy Keim
  Authors: Hughes, Larry J.; Epperson, Ann; Williams, Tammy Keim
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology; Geotechnology; Deploying Transportation Research-Doing Things Smarter, Better, Faster
  Session: 431
  Paper Number: 13-2182
  Practice-Ready: Yes
• A Project Delivery Selection Matrix for Highway Design and Construction
  Abstract: Determining an appropriate delivery method for highway projects is a complex decision. This paper presents a decision support approach to assist highway agencies in evaluating and selecting the most suitable delivery method for their projects. The approach uses a matrix to consider three fundamental delivery methods currently in use by the highway industry: design-bid-build (DBB), design-build (DB), and construction manager/general contractor (CM/GC). The approach, which is in use by the Colorado Department of Transportation (CDOT), includes four primary selection factors (delivery schedule, complexity and innovation, level of design, and initial project risk assessment) and four secondary selection factors (cost, staff experience/availability, level of oversight and control, and competition and contractor experience) in the delivery decision. The research identified these eight selection factors, along with opportunities and challenges for each delivery method, through literature and tested through discussions and workshops with innovative contracting leaders from the CDOT, the Federal Highway Administration (FHWA), the American Council of Engineering Companies (ACEC), Associated General Contractors of America (AGC), and the University of Colorado. The approach enables an initial risk assessment to occur early in the project development process and prior to the project delivery decision. The project delivery selection matrix promotes a better understanding of project goals, risks, opportunities, and enhances alignment among project participants. The approach has been successfully tested and implemented through eight projects of varying scope throughout Colorado. This paper presents the project delivery selection matrix along with an illustrative case study to demonstrate the results. The research provides a defensible and repeatable process for highway agencies to select an appropriate delivery method for their projects.
  Authors: Tran, Daniel Q.; Harper, Christofer M.; Molenaar, Keith R.; Haddad, Nabil F.; Scholfield, Mark M.
  Authors: Tran, Daniel Q.; Harper, Christofer M.; Molenaar, Keith R.; Haddad, Nabil F.; Scholfield, Mark M.
  Year: 2013
  Document Type: Paper
  Subject: Construction
  Session: 238
  Paper Number: 13-2260
  Practice-Ready: Yes
• Wireless Accelerometer-Based Automatic Vehicle Classification Prototype System
  Abstract: Automatic Vehicle Classification (AVC) systems provide data about vehicle classes that are used for many purposes. This paper describes a prototype axle count and spacing-based AVC system using wireless accelerometers and magnetometers. The accelerometers detect vehicle axles and the magnetometers report vehicle arrivals and departures and estimate speed. The prototype system is installed on I-80 at Pinole, CA and tested under various traffic conditions. Video images and reports from a nearby commercial Weigh-In-Motion (WIM) station provide ground truth to evaluate the performance of the system, including classification, axle spacing and vehicle counts. The results show the prototype AVC system is reliable in classifying vehicles even under congested traffic with 99% accuracy.
  Authors: Ma, Wenteng; Xing, Daniel; McKee, Adam; Bajwa, Ravneet; Flores, Christopher; Fuller, Brian; Varaiya, Pravin P.
  Authors: Ma, Wenteng; Xing, Daniel; McKee, Adam; Bajwa, Ravneet; Flores, Christopher; Fuller, Brian; Varaiya, Pravin P.
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 353
  Paper Number: 13-2261
  Practice-Ready: Yes
• Effectiveness of Reserved Bus Lanes in Arterials
  Abstract: There were two main goals in this investigation; first, modeling capacity for articulated buses in Arterials, and, second, the analysis of the representative parameters and their interrelationships in relation to the degree of platform reserve and bus lane segregation. Two cases in Madrid-Spain are considered, and a thord in Merida-Venezuela: In Madrid, bus lines 27 and 70, and the only bus line 1 of the Trolleybus Transport System (TTS), in Merida. These systems are selected under basic criteria that simplify the analysis: similar mode that suppresses inherent factors from vehicle design; bus stop infrastructure using two fare payment methods; and bus-lane with different reserve degree and segregation elements. The available methodology in the Transit Capacity and Quality of Service Manual (TCQSM) was used, and a solid bus dwell-time assessment due to boarding and alighting passengers –as the most influential parameter in the capacity– was measured. These new prediction laws were considered in the methodology. Results show the effectiveness of each system and allowed the calculation of the maximum theoretical capacity and its variability range in robust form. The work is part of a wider project to analyze the influence of reserved bus lane in operational parameters.
  Authors: Moreno, Emilio; Romana, Manuel G.; Martinez, Oscar
  Authors: Moreno, Emilio; Romana, Manuel G.; Martinez, Oscar
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 592
  Paper Number: 13-2283
  Practice-Ready: Yes
• Experimental Study on Characteristics of Base Friction for Concrete Pavement Structure in China
  Abstract: The restraint between the slab and the base of a concrete pavement structure is an important factor that should be taken into consideration when designing a concrete pavement. Excessive restraint can lead to unexpected distresses due to the daily cycle of ambient thermal influence and the changing moisture conditions that are ultimately detrimental to the performance of the pavement. Reasonable evaluation of base friction contributes to configuring joint sealing, slab thickness and reinforced steel.Semi-rigid base, mostly made of cement stabilized crushed stone, has been widely used as the typical base for cement concrete pavement in China. Usually, a polythene sheet would be placed between the concrete slab and the base to make the interface condition smooth. In certain cases, geotextile and asphalt bond breaker may also be used as a friction reducer.A series of push-off tests were performed under different conditions to study the characteristics of base friction for a typical concrete pavement in China. Polythene sheet, geotextile, emulsified asphalt and asphalt bond breakers of three different thicknesses(2cm, 4cm and 6cm) were placed between concrete slabs and semi-rigid bases. Concrete slabs were also cast directly on base with no bond breaker to study the influence of these factors on the characteristics of base friction. Also investigated in this study were the potential factors that affect the behavior of concrete slab under frictional drag, including rate of movements, slab thickness and number of movement cycles.
  Authors: Li, Sili
  Authors: Li, Sili
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 236
  Paper Number: 13-2291
  Practice-Ready: Yes
• Analyzing Use of Facebook Pages Among State Departments of Transportation
  Abstract: Social media has become a popular tool for both public agencies and the industry to publish news and interact with their customers. This study presents a review on how State Departments of Transportation (DOTs) use Facebook page to communicate with the public. As of June 12, 2012, 22 of the U.S. state DOTs have created Facebook pages. The objective of this paper is to analyze how users response to different types of content (e.g., links, status, photos and videos) that have been posted on the Facebook pages by state DOTs. A total of 17,131 posts, taken from April 18, 2008 to June 12, 2012, were extracted from Facebook and analyzed. The results of this study can help state DOTs better understand how the public reacts to the information provided through Facebook, so that they can adjust their social media strategies for more effective communication.
  Authors: Gao, Lu; Zhang, Zhanmin; Wu, Hui
  Authors: Gao, Lu; Zhang, Zhanmin; Wu, Hui
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting; Society
  Session: 505
  Paper Number: 13-2295
  Practice-Ready: Yes
• Traffic Microsimulation Approach to Evaluation of Vehicle Emissions on One-Way Versus Two-Way Streets: Case Study in Downtown Houston, Texas
  Abstract: Vehicles that run on one-way or two-way streets may generate totally different emissions. One-way streets can reduce the amount of conflicts between vehicles going to different directions, but sometimes create circuitous routes which may increase Vehicle Miles Traveled (VMT) and travel times, thus may increase emissions. Two-way streets can avoid circuitous routes, but create slower traffic due to the existence of more moving conflicts between vehicles, which may lead to increased stop, acceleration-and-deceleration activities, thus may also increase emissions but at a different degree. Further, regularities of such emission increases may be different for peak vs. non-peak hours. This paper intends to evaluate vehicle emissions for one-way and two-way streets for peak vs. non-peak hours to investigate which street configuration produces relatively lower emissions, attempting to help traffic engineers decide whether a conversion between one-way and two-way streets contributes to the improvement of air quality. The micro-traffic simulation model—VISSIM—is utilized to output the second-by-second speed and acceleration data for the purpose of emission estimation. The operating mode binning approach is used to calculate emission factors, and differences of generated emissions are adopted as the measure of effectiveness. The analysis shows that the two-way street network produces lower emissions, thus can better improve the air quality during non-peak hours. However, such improvement will be weakened during peak hours. Further, emissions from the two-way street network may eventually exceed those from the one-way street network when the traffic demand increases to certain level.
  Authors: Wang, Jinghui; Yu, Lei; Qiao, Fengxiang
  Authors: Wang, Jinghui; Yu, Lei; Qiao, Fengxiang
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-2218
  Practice-Ready: Yes
• Considering and Applying Driveway Design for All Users
  Abstract: NCHRP Project 15-35, Geometric Design of Driveways, was initiated to help address the lack of current comprehensive research and national design guidance for the design of driveway connections to roadways. The research initiated with this project included an extensive literature review, a survey of state agencies and contacts with interest groups, and field work to measure traffic attributes. The project produced two publications, a research report on the NCHRP website and the Guide for the Geometric Design of Driveways, NCHRP Report 659. This paper considers the following topics.* What design issues were identified? Current design practices may not adequately consider the range of all driveway users – bicyclists, motorists, and pedestrians. This section will also report vulnerability of various users, based on historic crash data.* What user attributes were found? The research conducted produced information about the driveway grades at which the undersides of vehicles may drag, and the speeds at which vehicles on urban arterials entered commercial driveways having radii ranging from 13 to 20 ft. * What design practices were recommended? To address the needs of all users, the design guide offered a number of design applications that differ from commonly-seen practices.This paper provides useful information for design consultants and local government professionals.
  Authors: Gattis, J. L.; Gluck, Jerome Steven; Barlow, Janet M.; Eck, Ronald W.; Hecker, William F.; Levinson, Herbert S.
  Authors: Gattis, J. L.; Gluck, Jerome Steven; Barlow, Janet M.; Eck, Ronald W.; Hecker, William F.; Levinson, Herbert S.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 397
  Paper Number: 13-2223
  Practice-Ready: Yes
• Multiobjective Optimization Model for Transit Fleet Resource Allocation
  Abstract: State and local transit agencies require government support to preserve their aging transit fleet. With passage of time, transit fleet gets older and requires maintenance cost to keep it operational. To provide services at a desired level, transit agencies require maintaining a minimum fleet size. Two imperative considerations from transit planning viewpoint are (1) remaining life of the total fleet, and (2) cost required to maintain the fleet size. When the former is a quality measure indicating the health of the fleet, the latter is an economic measure requiring minimum expenditure levels. Ideally, the agencies would like to maximize the total remaining life of the fleet and minimize the total cost required to maintain the fleet size. In this paper, the authors propose a multi-objective optimization model (MO) to simultaneously incorporate both objectives when subjected to budget and a number of operational constraints. The MO problem is solved by using classical weight sum approach by employing Branch and Bound Algorithm (BBA) that has proven to be better than other solution methodologies. The MO resulted in pareto optimal solutions with the possible trade-off between the two objectives. The model is applied to a real large scale transit fleet system in the state of Michigan, U.S. The case study results demonstrate, the proposed model is compact, efficient, robust and suitable for long range planning with multiple solutions to choose from a pareto optimal frontier. The correlation between decision variables and objective functions has been investigated in-depth and provides important insights. The proposed model can act as a tool for resource allocation for transit fleet among agencies for state and local agencies.Keywords: transit fleet, multi-objective optimization, branch and bound algorithm, pareto optimal
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Mathew, Tom V.; Khasnabis, Snehamay
  Authors: Mishra, Sabyasachee; Sharma, Sushant; Mathew, Tom V.; Khasnabis, Snehamay
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Planning and Forecasting; Public Transportation
  Session: 279
  Paper Number: 13-2225
  Practice-Ready: Yes
• Placement of Roadside Equipment (RSE) in Connected Vehicle Environment for Travel Time Estimation
  Abstract: Vehicle-to-Infrastructure (V2I) technology offers great potential in improving the safety and mobility in a transportation system. One mobility application is the travel time measurement in an urban road network. The presence of traffic control at intersections in an urban network makes it challenging for traditional traffic monitoring methods to provide accurate travel times. Several new technologies (e.g., Bluetooth) have been proposed to alleviate this problem. One of the features of V2I technology is probe vehicle data collection, where vehicles collect information such as their location and speed. The speed information can be used for travel time estimation. In this paper, one necessary and crucial aspect of travel time estimation using V2I technology is investigated. The paper proposes a methodology for determining the optimal placement of roadside equipment (RSEs) for travel time estimation in a V2I environment. A connected vehicle simulation test-bed of Boise, Idaho, was developed in the VISSIM traffic simulation software following the SAE J2735 standard. A hybrid performance measure, network coverage index, which combines travel time error and the number of links for which travel times are available was proposed. A Genetic Algorithm-based solution method was implemented in conjunction with the simulation test-bed to determine the optimal placement of different RSE deployments. The results indicate that the proposed methodology is capable of optimizing RSE locations in a V2I environment. Sensitivity analysis was also conducted by varying the market penetration rate and travel time estimation interval. The results indicated that higher penetration rates and bigger estimation intervals produced better coverage index values.
  Authors: Kianfar, Jalil; Edara, Praveen
  Authors: Kianfar, Jalil; Edara, Praveen
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 668
  Paper Number: 13-2232
  Practice-Ready: Yes
• Exercising Mega-Region Analysis Framework in Chesapeake Bay Area
  Abstract: Megaregions are a new geography that may well form the “nation’s operative regions when competing in the future global economy,” according to the March 2010 FHWA Strategic Plan. To assess the impact of policies and scenarios, a hypothetical Megaregion governing board, responsible for the broad welfare and economic competitiveness of an interacting region, will need to employ a broader set of tools than is typically used in typical Metropolitan Planning Organization (MPO) or State Department of Transportation (DOT) models. The analysis framework, resulting from a Federal Highway Administration’s Exploratory Advanced Research Program project, suggests an integrated model including travel driven by economic and land use decisions, and capturing effects on the environment, as well as enhancing the travel component to include long distance truck and person travel, the former driven by economic commodity flows. The paper discusses how this analysis framework was exercised in a proof-of-concept High Energy Price scenario for the Chesapeake Bay megaregion.
  Authors: Ducca, Fred; Weidner, Tara J.; Moeckel, Rolf; Mishra, Sabyasachee
  Authors: Ducca, Fred; Weidner, Tara J.; Moeckel, Rolf; Mishra, Sabyasachee
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 418
  Paper Number: 13-2236
  Practice-Ready: Yes
• Quasi-Experimental Study of Traffic Calming Measures in New York City
  Abstract: This paper provides a large-scale, rigorous evaluation of traffic calming projects in the U.S. The study area is New York City, which treated 391 streets with speed tables between 1996 and 2003. Based on crash frequencies for 5 years before treatment and 5 years after, for both treated streets and well-matched comparison streets, there is no evidence that New York City’s ambitious traffic calming program has led to a reduction in total crashes, pedestrian crashes, or injury crashes. This is in contrast to earlier, less carefully controlled evaluations that have reported significant reductions in crashes with traffic calming.
  Authors: Ewing, Reid; Chen, Li; Chen, Cynthia
  Authors: Ewing, Reid; Chen, Li; Chen, Cynthia
  Year: 2013
  Document Type: Paper
  Subject: Safety and Human Factors
  Session: 439
  Paper Number: 13-2242
  Practice-Ready: Yes
• Leaching Behavior of Aluminum, Arsenic, and Chromium from High-Carbon Fly-Ash Amended Highway Structural Fills
  Abstract: Coal power plants are very important in production of electricity in the United States. Approximately 50% of the electricity in Unites States is generated by coal combustion processes. As a result of this, large amounts of coal combustion byproducts, particularly fly ashes, are produced annually. Only 40% of these fly ashes can be reused successfully. The majority of the remaining landfilled or stockpiled fly ashes are high carbon fly ashes (HCFA). Continuous disposal of these HCFAs cause significant environmental and economical problems andhighway structures pose great potential for use of these landfilled HCFAs. While mechanical properties of the fly ash-amended highway base layers and embankments are deemed satisfactory, one key issue that precludes highway embankments built with fly ash is the potential for groundwater impacts caused by metals in the fly ash. To evaluate the environmental suitability, a series of column leach tests were conducted to determine the leaching of metals (Al, As and Cr) from fly ash amended soils. In addition, numerical computer modeling programs were used to predict the metal concentrations in soil vadose zone and groundwater. Results from laboratory tests indicated that metal concentrations increased with an increase in fly ash content and do not exceed the maximum concentration limits for drinking waters with few exceptions. Numerical modeling techniques predicted that leached metal concentrations decreased in the soil vadose zone with time and predicted concentrations of leached metals were below the environmental regulatory limits.
  Authors: Cetin, Bora; Aydilek, Ahmet H.; Li, Lin
  Authors: Cetin, Bora; Aydilek, Ahmet H.; Li, Lin
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2251
  Practice-Ready: Yes
• Evaluating Alignment Consistency for Mountainous Expressway in Design Stage: Driving Simulator-Based Approach
  Abstract: Evaluating design consistency is of great significance for safety evaluation on roadway design prior to its construction. Conventional design consistency showed little consideration of driving performance due to the limitation in data availability. More importantly, they were performed only on the existing roads. In this study, a simulated driving experiment was carried out in a high-fidelity driving simulator in Tongji University (Shanghai). A design stage four-lane (two-ways) mountainous expressway was implemented geo-based on the basis of the detailed road design blueprint. We attempted to establish a practical approach for evaluating its design consistency through investigating operating speed consistency, vehicle stability and vehicle lateral offset (vehicle trajectory). Specifically, the speed consistency is studied using the classic indicators ¨C the 85th speed reduction and 85th maximum speed reduction. The vehicle stability was evaluated using lateral acceleration, rollover coefficient and the conventional side-friction parameter. In the lateral offset analysis, the adjusted lateral offset was newly proposed, which is defined as the lateral offset from ideal vehicle trajectory. Utilizing the adjusted lateral offset can reflect the trajectory variation dependent on the characteristics of road geometry, which leads to the discovery of the inconsistencies in the studied mountainous expressway. The lateral acceleration and rollover coefficient could be considered as supplementary measures to provide insights into drivers¡¯ comfortableness as well as the rollover risk. Another contribution of this work is that we developed predicting models for the considered consistency measures. The purpose is to better understand the relationship between driving performance and roadway geometry characteristics, as well as to provide a practical formulation in a rigorous manner for road design consistency evaluation.
  Authors: Wu, Xingwei; Wang, Xuesong; Lin, Hangfei; He, Yefei; Yang, Le
  Authors: Wu, Xingwei; Wang, Xuesong; Lin, Hangfei; He, Yefei; Yang, Le
  Year: 2013
  Document Type: Paper
  Subject: Safety and Human Factors
  Session: 547
  Paper Number: 13-2309
  Practice-Ready: Yes
• Improve Rail Station Access Via Feeder Bus Network Optimization And Mode Shifts
  Abstract: In this study, an improved Feeder Bus Network Development Problem (FBNDP) model is presented. The proposed solution approach consists of three main components: Initial Solution Generation Procedure (ISGP), Network Features Determination Procedure (NFDP), and Solution Search Procedure (SSP). Tabu Search (TS) is used as a metaheuristic method in SSP to search a superior solution according to a given feasible solution. The inputs of the new FBNDP model are street network, demands from origins to the suburban rail station, and related parameters. The outputs are a feeder bus network system and service frequencies for each route. The complexities considered in this study include the consideration of various alternative modes, costs, more effective and efficient frequency determination methods, a multiple feeder bus route development process, and stop determination during the optimization procedure.
  Authors: Huang, Zhaodong; Liu, Rongfang
  Authors: Huang, Zhaodong; Liu, Rongfang
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 712
  Paper Number: 13-2328
  Practice-Ready: Yes
• Intraurban Rail Access: Policy Implications of Five Revealed Perspectives from a Q-Sorting Exercise in Three Australian Cities
  Abstract: This project advances current understanding of intra-urban rail passengers and their travel experiences in order to help rail industry leaders tailor policy approaches to fit specific, relevant segments of their target population. Using a Q sorting technique and cluster analysis, our preliminary research identified five perspectives occurring in a small sample of rail passengers, who varied in their frequency and location of rail travel as well as certain socio-demographic characteristics. Revealed perspectives (named to capture the gist of their content) included: ‘Rail Travel is About the Destination, Not the Journey’; ‘Despite Challenges, Public Transport is Still the Best Option’; ‘Rail Travel is Fine’; ‘Rail Travel? So Far, So Good’; and ‘Bad Taste for Rail Travel’. This paper discusses each of the perspectives in detail, and considers them in terms of tailored policy implications. An overarching finding from this study is that improving railway travel ‘access’ requires attention to physical, psychological, financial, and social facets of accessibility. For example, designing waiting areas to be more socially functional and comfortable has the potential to increase ridership by addressing social forms of access, decreasing perceived wait times, and making time at the station feel like time well spent. Even at this preliminary stage, the Q sorting technique promises to provide a valuable, holistic albeit fine-grained analysis of passenger attitudes and experiences that will assist industry efforts to increase ridership.
  Authors: Zuniga, Kelly Draper; Bunker, Jonathan Michael; Bevrani, Kaveh
  Authors: Zuniga, Kelly Draper; Bunker, Jonathan Michael; Bevrani, Kaveh
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Public Transportation
  Session: 352
  Paper Number: 13-2298
  Practice-Ready: Yes
• Development of Clegg Impact Value Thresholds for Minimizing Rutting of Cement-Treated Base Material Under Early Trafficking
  Abstract: In order to avoid early-age damage such as rutting, cement-treated base (CTB) materials must be allowed to cure before the pavement can be opened to early trafficking. One instrument shown to be effective in assessing the suitability of a CTB for early-age trafficking is the Clegg impact soil tester. In previous research, a Clegg impact value (CIV) threshold was proposed. That testing was conducted in northern Utah and consequently has limited application in other locations and with different CTB materials. Therefore, the objective of this research was to investigate the suitability of that CIV threshold in other conditions. Specifically, data were collected in Georgia, Texas and Idaho to supplement the Utah data. Following the field testing, the data were reduced on a site-specific basis, and CIV thresholds were selected for each site. The results indicate that the threshold is clearly a function of the 7-day unconfined compressive strength (UCS) of the CTB material, and a chart was developed to assist engineers with selecting appropriate CIV thresholds based on a specified 7-day UCS.
  Authors: Reese, G. Benjamin; Guthrie, W. Spencer
  Authors: Reese, G. Benjamin; Guthrie, W. Spencer
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 664
  Paper Number: 13-2299
  Practice-Ready: Yes
• Innovations in the Use of Utility Conflict Matrices to Optimize Project Development and Delivery
  Abstract: State departments of transportation (DOTs) accommodate public and private utility facilities within the state right of way based on state and federal utility accommodation rules. Due to the existence of utility facilities in the right of way, most transportation projects have a potential for utility conflicts at some stage of the project development process, such as interference between utility facilities and transportation design features.Delays and inefficiencies in activities related to the management of these conflicts have a tendency to proliferate into project letting and even construction, frequently resulting in higher bids, change orders and/or damage or delay claims, litigation by utility owners or agencies, safety concerns at the job site, frustration of the traveling public, and negative public perception about the project. Utility conflict tables, also known as utility conflict matrices (UCMs), are a common tool to organize and track utility conflict data used by many states. Research project R15-B (“Identification of Utility Conflicts and Solutions”) of the Strategic Highway Research Program 2 reviewed and documented current use of UCMs and developed optimized concepts that can contribute to standardization and optimization of the utility coordination process. This paper presents the results of these efforts and describes (a) the development of a prototype standalone utility conflict matrix that is compact (while at the same time useful to state DOTs) and facilitates tracking of utility conflict data, and (b) the development of a data architecture to facilitate an integrated approach to the management of utility conflicts and associated data.
  Authors: Kraus, Edgar; Quiroga, Cesar; Scott, C. Paul
  Authors: Kraus, Edgar; Quiroga, Cesar; Scott, C. Paul
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-2346
  Practice-Ready: Yes
• Is Smart Growth Associated with Reductions in CO2 Emissions?
  Abstract: The transportation sector is the second largest contributor to human-generated CO2 emissions. A key goal of the US Department of Transportation is to implement environmentally sustainable policies that can reduce carbon emissions from transportation sources. Smart growth developments are characterized by compact, mixed use, greater network connectivity and alternative mode friendly environments. These features may encourage reductions in vehicle travel and emissions. A better understanding of travel behavior in conventional and smart growth communities is needed to inform policies and make informed decisions. This study analyzes a behavioral dataset to answer whether smart growth developments are associated with lower CO2 emissions. Using a sample of 15,213 households from a recent (2009) travel behavior survey, sample selection models are estimated to capture the conditionality of emissions on the decision to drive or not by household members on an assigned day. The study found that the activity participation needs for 12% of the responding households allow them to either use alternative modes or not travel out-of-home. The rest of the sample traveled in an automobile and hence contributed to CO2 emissions. The study calculates CO2 emissions based on vehicle miles traveled and the fuel efficiency of the vehicle used for specific trips undertaken by household members. The framework developed in this study models whether CO2 emissions are associated with land use, socio-demographics, and preferences for information technology adoption. Tailpipe CO2 emissions are lower for households that reside in more mixed land use neighborhoods with denser roadway networks and better network connections in the neighborhood (on the order of 12%). As a long-term strategy, CO2 emission reductions from smart growth developments can be substantial.
  Authors: Wang, Xin; Khattak, Asad J.; Zhang, Yichi
  Authors: Wang, Xin; Khattak, Asad J.; Zhang, Yichi
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: ADC70
  Paper Number: 13-2350
  Practice-Ready: Yes
• Development and Comparison of Planning-Level and Data-Based Evaluation Tools of Intelligent Transportation Systems
  Abstract: Increasingly, transportation agencies are identifying performance measurement and benefits-cost analyses of their Intelligent Transportation Systems (ITS) programs as high priority tasks. There is a recognition that evaluating the benefits and costs of ITS implementations are necessary for both planning and operation purposes. The evaluation of ITS as part of the transportation system planning process has been mainly performed using sketch planning tools. However, the assessment of ITS at the planning for operations and operation levels require more detailed analysis and can be based on data from different sources and/or using more detailed modeling techniques such as macroscopic and microscopic simulation models.This paper compares the abilities of a planning level ITS evaluation tool and a real-world data-based evaluation tool, both developed by the authors, to assess the impacts of incidents and incident management strategies. The results presented in this paper confirm the importance of utilizing good estimates of incident rates and durations in the benefit analysis of incident management. In addition, the results indicate the importance of using accurate estimates of traffic demands in the evaluation tools. The results also confirm the ability of the deterministic queuing analyses, when using accurate traffic and incident input parameters, to produce results that are close to real-world measurements of delays, at least for the case study used in this paper.
  Authors: Xiao, Yan; Hadi, Mohammed; Ozen, Halit
  Authors: Xiao, Yan; Hadi, Mohammed; Ozen, Halit
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 668
  Paper Number: 13-2354
  Practice-Ready: Yes
• Simulation and Evaluation of Applying an Intelligent Taxi Operation System in Shenzhen, China, Using a Microscopic Multiagent Approach
  Abstract: This paper presents a microscopic multi-agent approach for simulating urban taxi service, where passengers¡¯ and taxi drivers¡¯ behaviors are captured at an individual level. Floating car data (FCD), from which real passenger travel demand data and real hourly road link travel time data are acquired, enable a realistic environment to be represented in this multi-agent system. This enables interventions (such as policies and regulations) on urban taxi services to be evaluated in a near-realistic environment. The multi-agent-based simulation system is then used to analyze the impacts of applying a city-level real-time taxi call and dispatch system in Shenzhen, China. The results suggest that the satisfactions of both passengers and taxi drivers can be considerably improved in terms of the average passenger waiting time and the average taxi utilization rate, respectively, by applying a real-time taxi call and dispatch system for urban taxi services. In such a system, the passenger participation rate, or the rate at which passengers take advantage of the proposed real-time taxi call and dispatch system, plays an important role.
  Authors: Yu, Lin-Jun; Peng, Zhong-Ren; Zhang, Jian
  Authors: Yu, Lin-Jun; Peng, Zhong-Ren; Zhang, Jian
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 648
  Paper Number: 13-2363
  Practice-Ready: Yes
• Feasibility and Advantages of Estimating Local Road VMT Based on GPS Travel Data
  Abstract: A critical part of the US national transportation data program is the Highway Performance Monitoring System (HPMS) and the reporting of vehicle miles traveled (VMT) on different levels of roadways. While the amount of travel on higher-level roads can often be reliably estimated from traffic counts and other data sources, existing heuristic methods for estimating lower-level and local road VMT suffer from the lack of ground truth data. At the same time, information on local roads across the nation is becoming increasingly important due to several emerging transport-related issues such as revenue allocation, emissions, and safety exposure.This paper develops a novel method for estimating local road VMT from GPS and other supplemental data sources, and investigates the associated statistical issues. The proposed method is applicable at the national, state, and any local levels, and is demonstrated in a case study in Maryland. By matching GPS data with GIS road networks, GPS-based travel surveys provide very reliable ground truth data for local road VMT estimation. GPS survey sample size and duration required for reliable VMT estimation are also analyzed within the case study. Results show that by lengthening survey duration, the required sample size could be reduced significantly. However, the sample size reduction effect of longer survey duration diminishes as the survey duration exceeds a certain threshold. Our case study and statistical analysis show that a 30-day GPS survey would reduce the required sample size by 50~60% compared to a single-day survey, and a 15-day GPS survey with 670 participating drivers could provide VMT estimates with a 5% margin of error at the 95% confidence level. Survey designer could employ longer survey duration to further reduce sample size or recruit more participants for a shorter survey. These findings suggest GPS-based surveys are feasible and cost-effective options for VMT estimation on different levels of roadways including local roads. Federal, state and local agencies may just use GPS-surveys already planned for other purposes (e.g., travel demand modeling and planning applications) for VMT estimation.
  Authors: Zhang, Lei; He, Xiang
  Authors: Zhang, Lei; He, Xiang
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-2402
  Practice-Ready: Yes
• Empirical Characterization and Interpretation of Hysteresis and Capacity Drop Phenomena in Freeway Networks
  Abstract: The objective of this study is to characterize hysteresis and capacity drop phenomena in freeway networks using commonly-available loop detector data from three different networks: Chicago (Illinois), Portland (Oregon), and Irvine (California). To explore the effects of variation in network topology and size on the network fundamental diagram (NFD), a comparison is made using the observed flow-occupancy diagrams of the selected freeway networks. The results provide further confirmation that findings presented in the literature for a limited number of networks are also valid for other freeway networks not previously studied. It is observed that freeway networks are more likely to exhibit an inconsistent hysteretic pattern in terms of shape and size depending on the spatial distribution of congestion over the network. Based on empirical observations, hysteresis loops are characterized by their shape and size. In this paper, two shapes are identified, characterized and named as H1 and H2. Also, it is proposed that the size of each hysteresis loop can be characterized by its width, height and the area covered by the hysteresis loop. It is postulated that the capacity drop phenomenon exists in freeway networks in a similar manner to individual freeway sections. Two types of capacity drop are identified. Capacity drop type I is associated with the inability of the freeway network to sustain its throughput at its peak value for a relatively long time and therefore, capacity drops while demand is still high and network is loading. Capacity drop type II is associated with the instability of network traffic when the network undergoes reloading (e.g. afternoon peak period) after an incomplete recovery from the initial loading (e.g. morning peak period). In some cases, this results in a lower capacity in the afternoon compared to the morning. Empirical results show that the observed phenomena are reproducible on different days and for different networks.
  Authors: Saberi, Meead; Mahmassani, Hani S.
  Authors: Saberi, Meead; Mahmassani, Hani S.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 841
  Paper Number: 13-2391
  Practice-Ready: Yes
• Leaching of Alkaline Substances and Heavy Metals from Recycled Concrete Aggregate Used as Unbound Base Course
  Abstract: There is an increased trend towards use of recycled concrete aggregate (RCA) in construction. However, concerns have been expressed about the highly alkaline leachate from RCA in laboratory studies and associated high-pH leaching patterns and heavy metal release from RCA (e.g., Cr, Pb, and As). In this study, seven samples of RCA from a wide geographical area were investigated. Physical, chemical, and mineralogical properties were characterized, and laboratory column leaching tests were conducted. Two field test sites were installed and instrumented, one at the MNROAD facility in Minnesota and a second at surface parking facility on the campus of the University Wisconsin-Madison. The MNROAD site showed a neutral leachate pH between 6.5 and 8.0 after 7 months of service life (1.2 pore volumes of flow); however, pH from column leaching tests ranged between 11.0 and 12.5 and showed no decline over 100 pore volumes of flow (PVF). Due to the large difference between the field and laboratory results, two samples of RCA in Wisconsin, one from a recent demolition of concrete pavement (WR-F) and the other from an RCA stockpile with an age of 5-10 years (WR-SP), were used in the Wisconsin field site to verify the Minnesota data and investigate the long-term leaching of alkaline compounds and heavy metals. WR-F RCA started with a high leachate pH (12.6) and remained constant for the first 5 pore volumes of flow (PVF); however, WR-SP RCA started at a lower pH (7.3) but with a gradually increasing trend, up to pH = 11.9 for the first 2 PVF. The pH from both RCAs were higher than the USEPA drinking water standard. Arsenic, chromium, lead, and selenium in the RCA field leachate were also observed to be higher than the maximum contaminant level (MCL) for the USEPA drinking water standard.
  Authors: Chen, Jiannan; Tinjum, James M.; Edil, Tuncer B.
  Authors: Chen, Jiannan; Tinjum, James M.; Edil, Tuncer B.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Materials
  Session: 746
  Paper Number: 13-2412
  Practice-Ready: Yes
• New Procedure for Estimating Cable Force in Cable-Stayed Bridge
  Abstract: In structural health monitoring of the cable-stayed bridges, estimation procedure for the cable tension influences the accuracy of monitoring system. Although some formulas are used in many monitoring systems, the results from these formulas are not accurate because they neglect the initial deflection, the natural frequency changing, and the initial curvature shortening of a oscillating cable. This paper presents a new estimation procedure that considers these neglected effects in the existing formulas and achieves the modified accuracy in estimating the tension force in the cable. Considering the initial deflection of the cable at the static status derives a clear explanation about the natural frequency changing for the change of the slenderness ratio of the cable. And by considering the stretching force induced by the initial curvature shortening, the additional forces acting on the supports of the cable conservatively are also investigated. In this paper, the concept of total tension force is proposed to increase the accuracy in tension force estimation for the cable. The re-estimation for the cable-stayed Alamillo Bridge, Spain shows that the new procedure estimates tension force of the cables more accurately and that this can be used as an alternative procedure in the structural health monitoring system.
  Authors: Choi, Dong-Ho; Park, Wan Soon; Nassif, Hani
  Authors: Choi, Dong-Ho; Park, Wan Soon; Nassif, Hani
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Maintenance and Preservation
  Session: 508
  Paper Number: 13-2407
  Practice-Ready: Yes
• The Hidden Life Saver? Unattended Locker Box Logistics for Faster and More Efficient Hospital Supply
  Abstract: The efficient flow of goods into hospitals is disrupted by the presence of time critical (urgent) items in the chain encouraging sub-optimal vehicle fleet operations. Furthermore, the fast delivery of such items can often become stalled by the transition between the external and internal supply chains, leading to duplicate ordering. These issues result in increased volumes of hospital-related traffic and a delay in the delivery of care to patients. An unattended electronic locker bank, comprising individual lockable boxes to which different urgent items can be delivered is proposed as a potential solution with the aims of: separating urgent and non-urgent goods in the chain, thereby enabling consolidation of non-urgent consignments; and, bypassing the traditional route of supply. The feasibility of this concept was tested in the context of Great Ormond Street Hospital for Children in London using a database of consignment movements to assess physical requirements of the locker bank, using a hill climbing optimization technique; and, qualitatively using interviews with key members of staff. Results of the quantitative analysis indicated that a locker bank measuring 3.33m (10.93ft.) in length, 1.7m (5.58ft.) height and 0.8m (2.62ft.) depth, comprising of 11 partitions would be required to accommodate 100% of all urgent consignments passing into the hospital during a typical week. Staff perceptions of the locker bank concept were largely positive suggesting the locker box could improve the speed and quality of healthcare delivered to patients.
  Authors: Bailey, Gavin; Cherrett, Tom; Waterson, Ben; Long, Robert
  Authors: Bailey, Gavin; Cherrett, Tom; Waterson, Ben; Long, Robert
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Planning and Forecasting
  Session: 407
  Paper Number: 13-2421
  Practice-Ready: Yes
• Development of Enhanced Alaska Pavement Preservation Program and Strategy Selection Guide
  Abstract: Alaska Department of Transportation and Public Facilities (AKDOT&PF) would like to enhance their existing pavement preservation management program by utilizing effective pavement preservation treatments for cold regions so that pavement life extension can be achieved and the need for more costly rehabilitation deferred. By collaborating with the California Pavement Preservation Center and the Alaska University Transportation Center (AUTC), AKDOT&PF has recently completed a pavement preservation research project to improve its pavement preservation program. The research tasks included (a) conducting an international survey of cold regions on pavement preservation; (b) reviewing literature on cold region pavement preservation treatments; (c) monitoring existing preservation treatments used by Alaska; (d) developing a pavement preservation database; and (e) creating an online treatment selection computer program. The pavement preservation treatment tracking database is a web-based online program which includes the standard types of pavement preservation strategies used in Alaska; pavement construction, traffic, weather, and other performance related information; an integrated Google Map function to show the location of the pavement preservation projects; and multiple pavement condition survey results with supporting documents. The strategy selection program is integrated within the pavement preservation database. It utilizes the results of the survey and other information on Alaska treatments to conduct treatment strategy selection and life cycle cost analysis. Workshops have been given on the preservation treatments used in cold regions and use of the database and the strategy selection process. The tools developed for AKDOT&PF should be very helpful for long term implementation of an effective pavement preservation program. Other agencies could learn from Alaska’s experience.
  Authors: Cheng, DingXin; Hicks, R. Gary; Parsons, Angela; Zubeck, Hannele K.; Liu, Juanyu; Mullins, Anthony
  Authors: Cheng, DingXin; Hicks, R. Gary; Parsons, Angela; Zubeck, Hannele K.; Liu, Juanyu; Mullins, Anthony
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Pavements
  Session: 256
  Paper Number: 13-2432
  Practice-Ready: Yes
• Abating CO2 and SOx Emissions from Container Shipping: the Articulation Between Deep Sea Shipping and Feedering in Sulfur Emission Control Areas
  Abstract: This paper deals with the impacts on the container shipping markets of two future environmental policies aimed at reducing ship-based emissions: the low-sulfur fuel requirements from MARPOL in Sulfur Emission Control Areas (SECA) and a European market-based instrument on CO2 emissions. Two regulatory scenarios are defined as well as a cost model for liner services. The paper assesses the cost implications as of 2018 of sulfur and CO2 policies for a typical North Europe-Asia service, and two feeder lines in North Europe, articulated with this transcontinental service through transshipments. The results are examined through a comparative evaluation of the impacts of these policies on deep sea shipping and feedering, depending on the options of compliance to the low-sulfur fuel requirements. A discussion on the possible strategies of reorganization of the container maritime networks to deal with these environmental extra costs leads to the conclusion that avoiding SECAs and CO2 scope for transcontinental routes and extending the feeder route to capitalize on the savings from scrubbing in SECAs might rarely prove cost-effective.
  Authors: Doudnikoff, Marjorie; Lacoste, Romuald
  Authors: Doudnikoff, Marjorie; Lacoste, Romuald
  Year: 2013
  Document Type: Paper
  Subject: Environment; Marine Transportation
  Session: 342
  Paper Number: 13-2435
  Practice-Ready: Yes
• Bilevel Generalized Least-Square Estimation of Dynamic Origin-Destination Matrix for Urban Network Using Probe Vehicle Data
  Abstract: Methods of estimating dynamic origin-destination (OD) matrices for urban networks from probe vehicle data are explored. A speed-density function is derived and fitted for different types of roads using the maximum likelihood method. A Bayesian method (BM) that carefully incorporates prior information and an ordinary method (OM) are both used to estimate link flows from probe vehicle speed. A DTA-based bi-level generalized least-square (GLS) estimator considering the distance between the estimated and target OD matrices as well as the distance between the calculated and observed link flows is formulated so as to estimate dynamic OD matrices from estimated link flows. In the iterative solution procedure, the upper level is solved using the extended Bell algorithm, while the commercial DTA system VISSIM is applied to produce the assignment matrix in the lower level. A medium-size signalized network in Tokyo is modeled in a case study, in which BM and OM are compared both in link flow estimation and OD matrix estimation. Further, the bi-level GLS estimator and bi-level OLS (ordinary least-square) estimator are implemented and then compared in OD estimation. The results validate the proposed bi-level GLS estimator.
  Authors: Cao, Peng; Miwa, Tomio; Yamamoto, Toshiyuki; Morikawa, Takayuki
  Authors: Cao, Peng; Miwa, Tomio; Yamamoto, Toshiyuki; Morikawa, Takayuki
  Year: 2013
  Document Type: Paper
  Subject: Planning and Forecasting
  Session: 231
  Paper Number: 13-2466
  Practice-Ready: Yes
• Need for Effective Technology Transfer to Ensure the Sustainability of the Otta Seal
  Abstract: The Otta (graded aggregate) seal technology originated in the Otta valley in Norway in the 1960s. This type of bituminous seal was first introduced to Botswana in the late 1970s with design and construction being initially undertaken in-house and, subsequently, by the private sector. However, a somewhat haphazard approach to the transfer of this relatively new technology from the public to the private sector was largely responsible for initially suppressing the uptake of this innovative type of surfacing despite its eminent suitability for use with locally available, marginal quality aggregates. Many lessons have been learned from this experience which are likely to be useful to other countries where the introduction of the Otta seal is being contemplated. The primary objective of this paper is to highlight the critical importance of undertaking effective technology transfer to ensure the sustainability of any new type of technology, such as the Otta seal. The paper considers the path from research to implementation of new technology, including the typical constraints and barriers that are faced in the African region. In the context of the Otta seal experience in Botswana, the paper then identifies typical barriers and constraints to its ready adoption by the private sector and proposes measures for overcoming them. The paper concludes that a carefully crafted, pro-active approach to technology transfer is necessary to ensure the sustainability of the Otta seal in countries where it is being introduced for the first time.
  Authors: Pinard, Michael Ian
  Authors: Pinard, Michael Ian
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design; Pavements
  Session: 245
  Paper Number: 13-2472
  Practice-Ready: Yes
• Transit Assignment Model Incorporating Dwell Time
  Abstract: The transit assignment problem with consideration of bus dwell time is analyzed in this paper. The links in a transit network can be classified into four types: on-board links, alighting links, boarding links and dummy links reflecting the bus dwelling behavior at the bus stations. Accordingly, the travel time functions on these links can be analyzed. This paper first proposes a new equation for the bus dwell time at each bus station, which is the maximum value between the passengers¡¯ boarding time and alighting time. Then, a dynamic programming based approach is used to describe the equilibrium passenger flow in the transit network. A gap function is subsequently proposed to formulate the equilibrium passenger flow, which is convenient to be solved by the Revised Optimal Strategy Algorithm and the Method of Successive Average. Finally, two numerical examples are adopted to validate the proposed methodology, where the bus dwell time function is calibrated using real survey data.
  Authors: Sun, LeiLei; Meng, Qiang; Liu, Zhiyuan
  Authors: Sun, LeiLei; Meng, Qiang; Liu, Zhiyuan
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 712
  Paper Number: 13-2485
  Practice-Ready: Yes
• Otta Seal Surfacing: Practical and Economic Alternative to Traditional Bituminous Surface Treatments
  Abstract: Natural gravel materials have traditionally been used for upgrading earth to gravel roads or for regravelling existing gravel roads. However, serious concerns have arisen regarding the continuous use of vast amounts of gravel - a non-renewable, finite resource - which is not only being rapidly depleted in many countries but is also unsustainable in the medium to long term. This has prompted road engineers to consider the use of low-cost bituminous surface treatments on these gravel roads as an alternative to regravelling. One type of surfacing that can provide an economic and practical alternative to traditional surfacings, such as the Chip seal, is the Otta seal. Unfortunately, lack of information regarding this relatively new type of bituminous surfacing has suppressed its more wide¬spread use, despite its excellent performance in a number of countries. In view of the above, this paper provides state-of-the-art information on the provision of the Otta seal surfacing as an economic and practical alternative to the more traditional bituminous surface treatments. The paper outlines the origin, properties, design and construction of the Otta seal and very briefly discusses its implementation impacts. Finally, the paper provides short information on the global use of the Otta seal.
  Authors: Overby, Charles
  Authors: Overby, Charles
  Year: 2013
  Document Type: Paper
  Subject: Construction; Design; Pavements
  Session: 245
  Paper Number: 13-2515
  Practice-Ready: Yes
• Benefits and Costs of Electric Vehicles for Public Finance: Integrated Valuation Model and Application to France
  Abstract: The upcoming launch of electric vehicles has financial impact on the public budget of a given country. Replacing a combustion engine vehicle by an electric vehicle entails fiscal effects not only due to announced supportive policy measures but also due to industrial factors that reflect changes in the manufacturing of a vehicle and in the provision of products and services throughout the vehicle’s operating life. Existing financial analyses have so far either only focused on the ‘obvious’, direct financial impacts resulting from policy measures, or have taken a socio-economic welfare approach incorporating environmental costs and benefits. Industrial factors have, to our knowledge, been left aside so far. This study delivers an exhaustive economic analysis taking all direct and indirect financial impacts of the introduction of electric vehicles on the public budget into account. Direct impacts refer to financial transfers due to subsidies and tax breaks. Indirect impacts refer to industrial factors which entail implications for i) the employment situation and therefore for salaries, social contributions by employers and employees and unemployment benefits and ii) tax revenues on the consumption side (VAT) and the production side. The valuation method is based on an input-output model of the productive economy, combined with mechanisms of fiscal and social transfer. The methodology is applied to France. Scenarios that vary assumptions on whether vehicle manufacturing and usage is taking place in- or outside the country are developed and analysed by their fiscal impact on the public budget.
  Authors: Windisch, Elisabeth; Leurent, Fabien M.
  Authors: Windisch, Elisabeth; Leurent, Fabien M.
  Year: 2013
  Document Type: Paper
  Subject: Economics
  Session: 298
  Paper Number: 13-2521
  Practice-Ready: Yes
• Quality Counts for Pedestrians and Bicyclists: Quality Assurance Procedures for Nonmotorized Traffic Count Data
  Abstract: As pedestrian and bicyclist monitoring increases among public agencies, it is critically important that data quality principles be included in the data collection practices. The main objective of this paper was to outline key quality assurance principles and their application to pedestrian and bicyclist traffic count data. Three key principles of quality assurance were described: 1) Quality assurance starts before data are collected; 2) "Acceptable” data quality is determined by its use; and 3)Measures can quantify different quality dimensions. The authors provide specific recommendations for 2 data quality measures: accuracy and validity.
  Authors: Turner, Shawn M.; Lasley, Philip H.
  Authors: Turner, Shawn M.; Lasley, Philip H.
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology; Pedestrians and Bicyclists
  Session: 640
  Paper Number: 13-2552
  Practice-Ready: Yes
• Quick-Scan Appraisal Method to Determine Cost-Effectiveness of Traffic and Demand Management Measures
  Abstract: This paper presents this quick-scan approach for assessing the cost-effectiveness of smaller and not-well demarcated transport measures that can be used as a first-scan while establishing packages to deal with certain transport problems. It adds to the available evaluation literature (see section 2) in relying on a combination of expert opinions as well as simple models rather than data intensive four-stage transport models. The approach consists of five steps, in the end yielding to an assessment of the cost-effectiveness of the considered measure. We illustrate the approach by applying it to determine the cost-effectiveness of a pricing measure, showing both the workings of the approach and the plausibility of the results. We conclude that the proposed method is applicable for providing a first, quick scan assessment. This assessment is useful in the first selection of planning, to support policy makers that need to choose in which (selection of) measures they need to invest, even if these measures have not yet been described or designed at a very detailed level.
  Authors: van Wee, Bert; Meurs, Henk; Perdok, Jan; Hoogendoorn, Serge
  Authors: van Wee, Bert; Meurs, Henk; Perdok, Jan; Hoogendoorn, Serge
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation
  Session: 282
  Paper Number: 13-2534
  Practice-Ready: Yes
• Mechanistic Structural Properties of Foamed Asphalt Stabilized Base Materials
  Abstract: Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP) and/or recycled concrete (RC) with a foamed asphalt binder. The pavement structural properties of FASB fall somewhere between conventional graded aggregate base (GAB) and hot mix asphalt (HMA). When FASB is used in place of GAB, the required thickness of the pavement section can be reduced, resulting in cost savings in addition to recycling benefits. The objective of this study is to address the most important performance related parameters of FASB material: stiffness and permanent deformation resistance, particularly with regard to the new mechanistic-empirical pavement design guide (MEPDG). Triaxial dynamic modulus tests were performed on cores of a field compacted and cured FASB mixture consisting of 40% RAP+ 60% RC+ 2.8% foamed asphalt to assess the distinct behavior of FASB under triaxial dynamic loading. Evaluation of the effects of stress states (confining pressure, and deviator stress), loading rate, and temperature on DYNAMIC MODULUS found that loading rate and temperature were the most significant factors influencing FASB stiffness. Insights were also gained regarding the influence of construction and curing conditions in the field. Triaxial repeated load permanent deformation (RLPD) tests were also performed to assess the resistance of FASB material to rutting. The results suggest satisfactory resistance of FASB material to rutting.
  Authors: Khosravifar, Sadaf; Schwartz, Charles W.; Goulias, Dimitrios
  Authors: Khosravifar, Sadaf; Schwartz, Charles W.; Goulias, Dimitrios
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 597
  Paper Number: 13-2544
  Practice-Ready: Yes
• An Analysis of Factors Contributing as Selection Criteria for Users of European Container Terminals
  Abstract: This paper examines the selection criteria for container shipping lines when choosing European container terminals. The purpose of the study is to determine the factors that are crucial for shipping lines when choosing European container terminals. Data has been collected via a questionnaire given to shipping lines calling at the Port of Rotterdam, the Port of Antwerp, and the Port of Hamburg, which are the main container hubs in Europe (measured by the number of TEUs handled annually). Descriptive statistics reveal that loading/discharging rate, handling charges, and service quality are the main attributes that influence port selection. The least important selection factors are personal contacts, investments by shipping lines, and value-added activities. The analysis also shows that hinterland connections are more important than value-added activities. This suggests that ports should focus more on developing good hinterland connections than on providing value-added activities. Factor analysis of the aggregate data is used to determine whether the 13 attributes could be partitioned into fewer, more meaningful factors. According to the results, 12 variables are loaded into two factors, which also seem to contain distinct elements: Factor 1 contains “Ports attributes” and Factor 2 contains the variables related to “Formal and informal relationships between ports and shipping lines.” This study will be useful for port authorities and terminal operators wishing to improve the efficiency and productivity of their port according to the requirements of their customers (that is, shipping lines).
  Authors: Saeed, Naima; Aaby, Bernt Christoffer
  Authors: Saeed, Naima; Aaby, Bernt Christoffer
  Year: 2013
  Document Type: Paper
  Subject: Freight Transportation; Marine Transportation; Terminals and Facilities
  Session: AW010
  Paper Number: 13-2561
  Practice-Ready: Yes
• Prediction of Typhoon Impact on Transportation Networks with Support Vector Regression
  Abstract: Typhoon (or Pacific tropical cyclones) is one of the major natural disasters in the world. Typhoons affect transportation network, cause serious delay, damage roads, decrease the reliability of infrastructure and threaten our lives. In order to avoid serious delay due to the unexpected damaged roads under typhoons, the prediction of typhoon impact on transportation networks is important to reduce the risk of lives. This research focuses on the prediction of typhoon impact on transportation networks with SVR. Support vector regression (SVR) has been used for regression problems and is capable of dealing with complex systems with small data. The input data in SVR model is the historical cumulative damaged roads and maximum cumulative precipitations under typhoons in the past years. The output data is the cumulative damaged roads in the target year. The calibrated model is then applied to predict possible damages and used to evaluate different traffic management strategies in a realistic simulation environment. The calibration results show that MAPE of SVR prediction model is 9.7%. Traffic strategies can be developed based on the prediction information and can significantly improve the network reliability.
  Authors: Hu, Ta-Yin; Ho, Wei-Ming
  Authors: Hu, Ta-Yin; Ho, Wei-Ming
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 603
  Paper Number: 13-2609
  Practice-Ready: Yes
• New Load Transfer Assembly for Jointed Concrete Pavements
  Abstract: Jointed concrete pavements continue to suffer from joint failure as the main distress and rehabilitation issue. The shear stress in the vicinity of dowel bars which is resulted from heavy traffic loads is the major factor that contributes to initiation of microcracks and joint faulting. A new load transfer assembly is introduced in this paper to be used in place of the conventional dowel bars. The introduced load transfer assembly was approved by the United States Patent Office as a new invention. The assembly comprises a spine and a plurality of dowel bars projecting from the spine where the spine comprises an elongated, freely rotating hinge. Finite element modeling was employed to evaluate the effect of using the new apparatus on the reduction of shear stress in concrete slabs. The finite element model was solved under various loading conditions and subgrade support. The obtained results showed that the suggested system reduces the shear stress level in the concrete by 15 to 20 percent. This amount of reduction in the shear stress can significantly reduce the shear-induced cracking near the joint. Furthermore, using the new load assembly was shown to be more effective on shear stress level than stabilizing the subgrade. The new invention has the capability of addressing curling and warping induced stresses as well as horizontal movement due to contraction and expansion. Furthermore, the new system prevents the dowel bars misalignment during new construction, as well as expediting the process of retrofitting damaged joints.
  Authors: Zeinali, Alireza; Mahboub, Kaymar C.; Southgate, Herbert F.
  Authors: Zeinali, Alireza; Mahboub, Kaymar C.; Southgate, Herbert F.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 236
  Paper Number: 13-2638
  Practice-Ready: Yes
• Development of Simulated Driving Cycles: Case Study of Waterfront Area in Toronto, Canada
  Abstract: Driving cycles are an important input for state-of-the-art vehicle emission models. Development of a driving cycle requires second-by-second vehicle speed for a representative set of vehicles. Current practice is to use standard driving cycles, like HWFET or SFTP-US06, however, these driving cycles reflect small samples of vehicles, do not reflect varying conditions by time of day, by vehicle type and cannot reflect forecast changes in traffic conditions. This paper introduces a new method to develop driving cycles using simulated data from a calibrated microscopic traffic simulation model in the Toronto Waterfront Area. The simulation method addresses some of the limitations with standard driving cycles. The simulation model is calibrated to reflect road counts, link speeds, and accelerations using a multi-objective genetic algorithm. The simulation method is applied to develop AM peak hour freeway driving cycles for light, medium and heavy duty trucks. The demonstration reveals differences in speed, acceleration, and driver aggressiveness between driving cycles for different vehicle types. These driving cycles are compared against a range of available driving cycles, showing different traffic conditions and driving behaviors, and suggesting a need for city-specific driving cycles. Emissions from the simulated driving cycles are also compared with EPA’s Highway Fuel Economy Driving Schedule (HWFET) showing higher emission factors for the Toronto Waterfront freeway cycles.
  Authors: Amirjamshidi, Glareh; Roorda, Matthew J.
  Authors: Amirjamshidi, Glareh; Roorda, Matthew J.
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-2648
  Practice-Ready: Yes
• Passive Force-Deflection Behavior for Zero- and Thirty-Degree Skewed Abutments
  Abstract: Accounting for seismic forces and thermal expansion in bridge design requires an accurate passive force-deflection relationship for the abutment wall. Current design codes make no allowance for skew effects on passive force; however, small-scale experimental results indicate that there is a significant reduction in peak passive force as skew angle increases for plane-strain cases. To further explore this issue large-scale field tests were conducted with skew angles of 0° and 30° with unconfined backfill geometry. The abutment backwall was 11-ft (3.35-m) wide by 5.5-ft (1.68-m) high and backfill material consisted of dense compacted sand. The peak passive force for the 30° skew was found to be 57% of the peak passive force for the 0° skew case which is in good agreement with the available laboratory and numerical results; however, this may suggest that backfill geometry has some effect on the reduction in peak passive force with respect to skew angle. Longitudinal displacement of the backwall at the peak passive force was found to be between 3% and 5% of the backwall height for both the 0° and 30° skew test which is consistent with previously reported values for large-scale passive force-deflection tests. Heave geometries for both the 0° and 30° tests were quite similar. In both cases the failure geometry extended approximately 4 ft to 5 ft (1.22 m to 1.52 m) beyond the edge of the pile cap and 16 ft (4.88 m) from the face of the cap when measured perpendicular to the backwall.
  Authors: Marsh, Aaron; Rollins, Kyle M.; Franke, Bryan; Smith, Jaycee; Palmer, Katie
  Authors: Marsh, Aaron; Rollins, Kyle M.; Franke, Bryan; Smith, Jaycee; Palmer, Katie
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Geotechnology
  Session: 209
  Paper Number: 13-2665
  Practice-Ready: Yes
• Microscopic Simulation of Transit Bus Emissions Under Transit Signal Priority and Alternative Technology
  Abstract: The benefits of public transit in terms of reducing transportation-related greenhouse gas (GHG) and air pollutant emissions is a topic that needs little introduction. The literature swells with studies comparing per-passenger emissions in transit with emissions from single occupancy vehicles, stressing the importance of increasing transit ridership. We argue that increasing transit ridership is not sufficient to achieve meaningful emission reductions at a regional level. In Montreal, transit operations and technology are in dire need for improvement and additional reductions in transit emissions largely depend on the types of fuels used and driving conditions. We microsimulated the operations and emissions of transit buses along a busy transit corridor and quantified the effects of two different fuels (conventional diesel and compressed natural gas) as well as a set of driving conditions on emissions. Results indicate that compressed natural gas (CNG) reduces GHG emissions by 8-12% compared to conventional diesel. However, the benefits of switching from conventional diesel to CNG are less apparent when the road network is uncongested. As congestion levels rise, the emission reductions associated with CNG improve. We also investigated the effects of bus operations on emissions by applying several strategies such as transit signal priority (TSP), queue jumper lanes, and relocations of bus-stops. Results show that TSP alone can reduce emissions by 14% and when combined with improved technology; a reduction of 23% is achieved. The reduction benefits are even more apparent when other transit operational improvements are combined with TSP.
  Authors: Alam, Ahsan; Hatzopoulou, Marianne
  Authors: Alam, Ahsan; Hatzopoulou, Marianne
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 503
  Paper Number: 13-2676
  Practice-Ready: Yes
• Methodology to Characterize Agriculture-Related Trucking on Low-Volume Rural Roads to Support Asset Management
  Abstract: This paper develops a methodology to characterize agriculture-related trucking on low-volume rural roads. The methodology considers truck trips from the field to intermediate storage facilities (field-to-storage) and from these facilities to market (storage-to-market). The methodology, which applies the transportation systems analysis approach, leverages knowledge from local producers through in-person interviews to qualitatively and quantitatively characterize the transportation supply and demand that generate truck flows. Flow characterization in terms of truck volumes and trip-making characteristics supports asset management decisions, such as maintenance timing and upgrade investments, in addition to providing information for forecasting future demand and infrastructure impacts.The development and application of the methodology contributes in three ways. First, it characterizes truck flows from field-to-storage, a segment of the agricultural supply chain seldom considered by previous research. Second, it demonstrates the extent of information concerning road usage and impacts available from producers. Third, results from the application of the methodology to a study region in Manitoba reveal that: (a) smaller truck types are more commonly used for the shorter field-to-storage trips than storage-to-market trips; (b) actual distance traveled exceeds desired distance traveled, owing mainly to infrastructure-related regulatory constraints; and (c) trip length distributions for the storage-to-market segment exhibit a relationship between trip length and type of truck and commodity. The methodology is transferrable across jurisdictions and scalable for different geographic and temporal scopes. The specific results presented in this paper, however, may not be representative of conditions in other regions.
  Authors: Enns, Garry A.; Reimer, Mark Jonathon; Regehr, Jonathan D.
  Authors: Enns, Garry A.; Reimer, Mark Jonathon; Regehr, Jonathan D.
  Year: 2013
  Document Type: Paper
  Subject: Design; Maintenance and Preservation; Pavements
  Session: 240
  Paper Number: 13-2666
  Practice-Ready: Yes
• Local Calibration Studies on DARWin-ME/Mechanistic-Empirical Pavement Design Guide Jointed Plain Concrete Pavement Performance Prediction Models
  Abstract: The AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement performance models and the associated AASHTOWare® pavement design software of DARWin-ME are nationally calibrated using design inputs and distress data largely from the national Long-Term Pavement Performance (LTPP). Further calibration and validation studies are necessary for local highway agencies’ implementation by taking into account local materials, traffic information, and environmental conditions. This study aims to improve the accuracy of MEPDG/ DARWin-ME pavement performance predictions for Iowa pavement systems through local calibration of MEPDG prediction models. A total of 70 sites for both jointed plain concrete pavement (JPCP) and Hot Mix Asphalt (HMA) pavement representing Iowa conditions were selected. The accuracy of the nationally calibrated MEPDG prediction models for Iowa conditions was evaluated. The local calibration factors of MEPDG performance prediction models were identified using both linear and nonlinear optimization approaches. The local calibration improved the accuracy of JPCP performance predictions and HMA rutting predictions. A comparison of MEPDG predictions with those from DARWin-ME was performed to assess if the local calibration coefficients determined from MEPDG version 1.1 software are acceptable in DARWin-ME, which has not been addressed before. Few differences are observed between DARWin-ME and MEPDG with national and local calibrated models for: (1) faulting and transverse cracking predictions for JPCP, and (2) rutting, alligator cracking and smoothness predictions for HMA. With the use of locally calibrated JPCP smoothness (IRI) prediction model for Iowa conditions, the prediction differences between DARWin-ME and MEPDG are reduced. Finally, recommendations are presented on the use of identified local calibration coefficients of DARWin-ME/MEPDG for Iowa pavement systems.
  Authors: Kim, Sunghwan; Ceylan, Halil; Di, Ma; Gopalakrishnan, Kasthurirangan
  Authors: Kim, Sunghwan; Ceylan, Halil; Di, Ma; Gopalakrishnan, Kasthurirangan
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 267
  Paper Number: 13-2667
  Practice-Ready: Yes
• Pullout Resistance Factors for Inextensible MSE Reinforcements Embedded in Sandy Backfill
  Abstract: This paper presents results from a laboratory program of 402 pullout tests of inextensible reinforcements used for Mechanically Stabilized Earth (MSE) walls. Results focus on evaluation of pullout resistance factors for sandy backfill and MSE reinforcement combinations used by the Texas Department of Transportation (TxDOT). This project uses Texas Tech University’s large-scale MSE Test Box with dimensions of 12 feet x 12 feet x 4 feet and an applied overburden capacity of 40 feet of backfill. This test box facilitates pullout testing at a scale not unlike typical field construction. The research design evaluates pullout resistance factors for both ribbed strip and welded grid reinforcements for a variety of independent variables including overburden pressure, reinforcement length, skew or splay angle, level of compaction, grid wire size, and grid geometry including both transverse and longitudinal wire spacing. We use statistical analyses to interpret the data within the context of published AASHTO design guidance for inextensible MSE reinforcements.
  Authors: Lawson, William D.; Jayawickrama, Priyantha Warnasuriya; Wood, Timothy A.; Surles, James
  Authors: Lawson, William D.; Jayawickrama, Priyantha Warnasuriya; Wood, Timothy A.; Surles, James
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Geotechnology
  Session: 209
  Paper Number: 13-2684
  Practice-Ready: Yes
• Global Sensitivity Analysis of Jointed Plain Concrete Pavement Mechanistic-Empirical Performance Predictions
  Abstract: The new AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) provides pavement analysis and performance predictions under various “what-if” scenarios. The MEPDG performance predictions for the anticipated climatic and traffic conditions will depend on the values of the input parameters that characterize the pavement materials, layers, design features, and condition. This paper proposes comprehensive global sensitivity analyses (GSA) methodology to evaluate jointed plain concrete pavement (JPCP) performance predictions to MEPDG inputs under five climatic conditions and three traffic levels. MEPDG inputs evaluated in the analyses include traffic volume, layer thicknesses, material properties, groundwater depth, geometric parameters, and others. Correlations among MEPDG inputs were considered where appropriate. The GSA varied all inputs simultaneously across the entire problem domain for each of the 15 base cases (5 climates x 3 traffic levels). Two response surface modeling (RSM) approaches, multivariate linear regressions (MVLR) and artificial neural networks (ANN or NN), were developed to model the GSA results for evaluation of MEPDG input sensitivities across the entire problem domain. The ANN-based RSMs developed for the MEPDG JPCP performance predictions not only provide robust and accurate representations of the complex relationships between MEPDG inputs and distress outputs but also capture the variation of sensitivities across the problem domain. The design limit normalized sensitivity index (NSI) proposed in this study provides practical interpretation of sensitivity relating a given percentage change in a MEPDG input to the corresponding percentage change in predicted distress relative to its design limit value.
  Authors: Ceylan, Halil; Gopalakrishnan, Kasthurirangan; Kim, Sunghwan; Schwartz, Charles W.; Li, Rui
  Authors: Ceylan, Halil; Gopalakrishnan, Kasthurirangan; Kim, Sunghwan; Schwartz, Charles W.; Li, Rui
  Year: 2013
  Document Type: Paper
  Subject: Design; Pavements
  Session: 267
  Paper Number: 13-2690
  Practice-Ready: Yes
• Decarbonization of Toll Plazas: Impact Assessment of Toll Collection System Management
  Abstract: Transport climate change impacts have become a worldwide concern. The use of Intelligent Transport Systems (ITS) could contribute to a more effective use of resources in toll road networks. Management of toll plazas is central to the reduction of greenhouse gas (GHG) emissions, as it is there that bottlenecks and congestion occur. This study focuses on management strategies aimed at reducing climate change impacts of toll plazas by managing toll collection systems. These strategies are based on the use of different collection system technologies – Electronic Toll Collection (ETC) and Open Road Tolling (ORT) – and on queue management. The carbon footprint of various toll plazas is determined by a proposed integrated methodology which estimates the CO2 emissions of the different operational stages at toll plazas (deceleration, service time, acceleration, and queuing) for the different toll collection systems. To validate the methodology, two main-line toll plazas of a Spanish toll highway were evaluated. The findings reveal that the application of new technologies to toll collection systems is an effective management strategy from an environmental point of view. The case studies revealed that ORT systems lead to savings of up to 70% of CO2 emissions, while ETC systems save 20%. Furthermore, queue management can offer a 16% emissions savings when queue time is reduced by 116 seconds. The integrated methodology provides an efficient environmental management tool for toll plazas. The use of new technologies is the future of the decarbonization of toll plazas.
  Authors: Hernandez, Sara; Monzon, Andres; Sobrino, Natalia
  Authors: Hernandez, Sara; Monzon, Andres; Sobrino, Natalia
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-2687
  Practice-Ready: Yes
• New Consistency Index Based on Inertial Operating Speed
  Abstract: Road crashes occurrence depends on several factors, being the design consistency one of the most important. It refers to the conformance of highway geometry to drivers’ expectations.A new consistency model for evaluating the performance of tangent-to-curve transitions at two-lane rural roads is presented. It is based on the Inertial Consistency Index (ICI), defined for each transition. It is calculated at the beginning point of the curve, as the difference between the average operating speed of the previous 1 km road segment (inertial operating speed) and the operating speed at this point.88 road segments, which included 1,686 tangent-to-curve transitions, were studied in order to calibrate ICI and its thresholds. The relationship between those results and the crash rate associated to each transition has been analyzed. It has been pointed out that the higher the ICI is, the higher the crash rate is, thus increasing the probability of accidents to take place. Similar results were obtained from the study of the relationship between ICI and the weighted average crash rate of the corresponding group of transitions.A graphical and statistical analysis established that road consistency may be considered good when ICI is lower than 10 km/h; poor when ICI is higher than 20 km/h; and fair otherwise.A validation process has been carried out considering 20 road segments. The obtained ICI values were highly correlated to the number of crashes occurred at the analyzed transitions. Hence, the Inertial Consistency Index (ICI) and its consistency thresholds resulted in a new approach for consistency evaluation.
  Authors: Garcia, Alfredo; Llopis-Castello, David; Camacho-Torregrosa, Francisco Javier; Perez-Zuriaga, Ana Maria
  Authors: Garcia, Alfredo; Llopis-Castello, David; Camacho-Torregrosa, Francisco Javier; Perez-Zuriaga, Ana Maria
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 726
  Paper Number: 13-2694
  Practice-Ready: Yes
• Less Money, Better Policy Possible
  Abstract: As the transportation agencies across the country are forced to deal with declining funding levels, much attention is paid to what will be lost as a result of these reductions. However, not enough attention is being given to what agencies can do to not only manage under tight budgets but also make tremendous advancements in how projects are delivered in a way that is more accountable and transparent to citizens. This maybe an era of smaller transportation programs; but it can also be a time of greater leadership and public policy.It was with this in mind, that the Kansas Department of Transportation (KDOT) embarked on a multi-year experiment to reinvent transportation planning and project selection processes in an effort to achieve greater support through stakeholder consultation, collaboration, and adoption of improved and expanded methods for ranking and selecting projects that appeal to broader issues of public concern (such as job creation) instead of merely engineering measures of need. Eight years of experimentation in consultation, collaboration and revising processes provides many lessons for the transportation community, which may be applicable in whole or in part for other state or regional transportation agencies. This paper critically examines the methods and tools used by KDOT, including surveys, collaborative planning efforts, social media outreach, economic impact analysis and expanded project selection processes. The results of this effort are both the passage of a new 10-year transportation program by the Kansas Legislature in 2010 and its successful implementation in 2011.
  Authors: Lorenz, Julie; Douglas, Lindsey
  Authors: Lorenz, Julie; Douglas, Lindsey
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management
  Session: 388
  Paper Number: 13-2729
  Practice-Ready: Yes
• Knowledge Management as Part of Strategic Workforce Development in Transportation Agencies
  Abstract: Organizations facing turnover of employees due to retirements, new demands, budget constraints, and other unforeseen circumstances are at risk for large amounts of critical knowledge walking out the door unless steps are taken to preserve it within the organization. Organizational support of knowledge transfer mechanisms that address both the tacit (unwritten experience) and explicit (codified) knowledge is vital to avoid this loss and to quickly on-board new employees. This submission provides a synopsis of NCHRP Project 20-81 and resulting Report 685, entitled: Guide to Implementing Strategies to Attract and Retain a Capable Transportation Workforce as it relates to implementing successful KM programs within transportation agencies. This paper also highlights the importance of KM programs in larger workforce development efforts while providing supplemental KM research and lessons learned. Finally, we provide a detailed description of the Virginia Department of Transportation’s award-winning knowledge management program.
  Authors: Cronin, Brian; Heinen, Beth; Hammer, Maureen L.; Horey, Jeff
  Authors: Cronin, Brian; Heinen, Beth; Hammer, Maureen L.; Horey, Jeff
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Data and Information Technology; Education and Training
  Session: 681
  Paper Number: 13-2705
  Practice-Ready: Yes
• Wisconsin’s Method of Probing Portland Cement Concrete Pavement for Thickness Determination: Six-Year Statistical Review
  Abstract: The Wisconsin Department of Transportation (WisDOT) has used probing of fresh concrete to determine the thickness of Portland Cement Concrete (PCC) pavements since 1998. Two earlier studies which compared the results from probing and cores on WisDOT projects concluded that probing did provide an acceptable measure of pavement thickness, but it was recommended that an annual coring program be instituted to verify the probing results. This paper compares core depths with probe measurements for all the projects constructed by WisDOT from 2006 -2011 where both core and probe data were available. A total of 32 projects were analyzed representing over 6,600 probes and 1,200 cores. A statistical analysis was done to determine if the core and probe measurements gave the same results. A simulation model was developed to analyze the power of the t-test to predict if the two measurements are the same and to develop sample sizes needed to insure the two measurements differ only by a preselected amount. Results indicate that there are small, yet somewhat negligible in practice, differences between the core and probe methods of measurement. Recommendations are given for sample sizes needed based upon the size of the acceptable difference between the two methods.
  Authors: Whited, Gary C.; Stenhaug, Benjamin A.; Loh, Wei-Yin
  Authors: Whited, Gary C.; Stenhaug, Benjamin A.; Loh, Wei-Yin
  Year: 2013
  Document Type: Paper
  Subject: Construction; Pavements
  Session: 237
  Paper Number: 13-2718
  Practice-Ready: Yes
• Stabilization of High Sulfate Soils by Extended Mellowing
  Abstract: Using lime to stabilize expansive soils has been a preferred technique of practitioners for many years. However, heaving and premature pavement failures in lime-treated expansive subgrades containing sulfates led to the search for alternative stabilization techniques. Out of the several techniques developed, pre-compaction mellowing has potential to be effective in the stabilization of sulfate bearing soils. Yet this method still needs to be experimentally evaluated. In the current study, an attempt has been made to assess the stabilization effectiveness of pre-compaction mellowing on high sulfate soils. For this task, six natural expansive soils from the state of Texas, with sulfate contents varying from 200 ppm to 44,000 ppm, were collected. Soils with low sulfate contents were spiked with additional sulfates to make them high sulfate soils. Basic classification and chemical tests were performed to establish the clay mineralogy of the soils. Three different mellowing periods (0, 3 and 7 days) were studied. The test soils were treated with lime and allowed to mellow for the specified periods. Following the mellowing, the samples were subjected to three dimensional (3-D) volumetric swell, shrinkage and UCS tests. Reactive alumina and silica measurements were also attempted to study the consumptions of alumina and silica during sulfate-soil-lime reactions. It was observed that shrinkage was of no concern in treated soils since the shrinkage invariably reduced with lime treatment. In four of the six soils, pre-compaction mellowing successfully reduced sulfate-induced swell to a level below the natural expansive swelling. The UCS strengths of treated soils decreased slightly with mellowing. Reasons for the anomaly in UCS strengths and ineffectiveness of pre-compaction mellowing in two soils were explained.
  Authors: Puppala, Anand J.
  Authors: Puppala, Anand J.
  Year: 2013
  Document Type: Paper
  Subject: Geotechnology; Pavements
  Session: 664
  Paper Number: 13-2709
  Practice-Ready: Yes
• Measurement and Prediction of Coefficient of Thermal Expansion for Concrete Pavement Design in Georgia
  Abstract: The study to investigate the relationship between Coefficient of Thermal Expansion (CTE), aggregate type, gradations, and proportion of coarse and fine aggregate in mixture was conducted using the American Association of State Highways and Transportation Officials (AASHTO) T 336-11. Concrete specimens were fabricated in the laboratory to produce different mixes using Type I cement. Mix design variables were coarse and sand aggregate types, 2) fly ash type and content (Class C/Class F, High/Low), 3) air-entraining admixture (3%/6%), and 4) coarse aggregate contents (High Stone Volume/Low Stone Volume). For each combination of factors, five specimens from each batch were prepared for the CTE measurements and thus, total number of specimens tested in this study was 320. To properly account for the effect of aggregate content changes on the CTEs, the slump was held to approximately 2-inch on all the concrete mixture designs by adjusting the amount of water used in the mixes. The results showed that concretes composed of high stone volume of granite with manufactured sand have the lowest CTE while those composed of low stone volume of dolomite with siliceous natural sand have the highest CTE value. It implies that the stone volume, aggregate type, and sand type significantly affect the CTE value. In this study, a multiple regression model was also developed to estimate the CTE as a function of coarse aggregate and sand types and contents. The prediction model was validated with field cored specimens, and overall R-square value of the prediction model was over 86%.
  Authors: Kim, Sung-Hee; Jeong, Jin-Hoon
  Authors: Kim, Sung-Hee; Jeong, Jin-Hoon
  Year: 2013
  Document Type: Paper
  Subject: Materials
  Session: 206
  Paper Number: 13-2727
  Practice-Ready: Yes
• COMPARISONS OF DISCRETIONARY PASSENGER VEHICLE IDLING BEHAVIOR BY SEASON AND TRIP STAGE USING GPS AND OBD DEVICES
  Abstract: This study addresses the topic of discretionary passenger vehicle idling, using field data collected from 20 volunteers in Vermont. Each volunteer participated in two, two-week data collection periods, one in the summer and one in the winter. Overall, 15.6% of vehicle operating time was spent idling, consistent with the limited existing data on this topic. In addition, the paper describes a processing method used with in-vehicle GPS and OBD data that allows discretionary idling at the start and end of trips to be separated from the in-travel idling related to traffic or traffic control. Discretionary idling accounted for more than 6.5% of vehicle operating time. Discretionary winter idling events are found to be longer than summer idling events and, among idling events over 60 seconds, trip-start idling to be longer than trip-end idling. Both of these results re-affirm prior findings suggesting that there are opportunities for behavioral changes to reduce idling. The method used to extract discretionary idling is promising for widespread use and large sample data collection efforts. This method will be critical for the many communities that lack robust idling data when considering the costs and benefits of idling behavior change initiatives.
  Authors: Dowds, Jonathan R.; Sullivan, James; Aultman-Hall, Lisa
  Authors: Dowds, Jonathan R.; Sullivan, James; Aultman-Hall, Lisa
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 557
  Paper Number: 13-2766
  Practice-Ready: Yes
• Long-Term Maintenance of Culverts
  Abstract: According to the American Society for Civil Engineers more than 1.6 trillion dollars are needed to update the nation's mostly aging infrastructure through various bonds and public funds. However, there was a significant dissatisfaction with the manner the last stimulus funds were spent. This is partially due to unavailability of rational methods to allocate precious resources. There are significant advances in health monitoring and rating of transportation infrastructure including culverts. However, rational connection of the transportation infrastructure to maintenance expenditure is lacking, especially the long-term maintenance expenditure. Any maintenance expenditure should be justified such that net increase in the asset value should be less than the cost of rehabilitation, where the net worth of an asset should be based on performance rather than on book value. Also the justification for rehabilitation or replacement of transportation infrastructure including culverts should occur only if user cost of failure is comparable to the rehabilitation or replacement cost. In order to perform such analysis, the user cost of failure should be incorporated into the above analysis and this analysis should be performed based on the available and accepted rehabilitation technologies. In this manuscript such analysis is performed to develop a methodology for optimum long-term allocation of funds to maintain culverts. This procedure may be used for other transportation infrastructure.
  Authors: Meegoda, Jay N.
  Authors: Meegoda, Jay N.
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Maintenance and Preservation
  Session: 495
  Paper Number: 13-2818
  Practice-Ready: Yes
• Benefits of Standardization of Bus Transit Automated Vehicle Location Data Outputs to the Academic Community
  Abstract: Automatic Vehicle Location (AVL) systems offer transit agencies and the academic community vast quantities of data on the operation of bus transit networks. However turning this raw data into useful metrics that are of interest can be quite cumbersome and require a significant amount of processing of AVL log files. There would be many benefits to both transit agencies and academia if such metrics were output in a standardised format by the AVL system.This paper summarises existing data exchange standards used in the bus transit industry and explains the benefits of these. It then describes a recent project undertaken by London Buses to analyse dwell time data, and highlights the difficulties and costs involved collecting the basic data required for this analysis. It proposes that more data standards should be defined for data output by AVL systems. If these standards were then implemented by AVL vendors this would mean that transit agencies and academics could get easy access to useful information which otherwise would require much time and cost in obtaining.
  Authors: Robinson, Stephen
  Authors: Robinson, Stephen
  Year: 2013
  Document Type: Paper
  Subject: Passenger Transportation; Public Transportation
  Session: 226
  Paper Number: 13-2811
  Practice-Ready: Yes
• Translating Transportation Data Between Dissimilar-Resolution Linear Referencing Systems
  Abstract: The Wisconsin Department of Transportation (WisDOT) uses two separate linear referencing systems (LRSs) for complete statewide crash mapping. The State Trunk Network (STN) represents only state routes while the Wisconsin Information System for Local Roads (WISLR) includes all roads, with specific detail given to local routes. A functional link between the two systems has been developed that allows data to be translated from STN, a higher resolution representation, to WISLR, a lower resolution representation. While data is easily translated from high to low resolution, ambiguities arise when data is moved from low resolution to high resolution. Research presented in this paper identifies common problems associated with low to high resolution data translation and provides some rules and guidelines to accommodate these issues.
  Authors: Graettinger, Andrew J.; Morrison, Anthony Lane; Parker, Steven; Forde, Susie; Qin, Xiao
  Authors: Graettinger, Andrew J.; Morrison, Anthony Lane; Parker, Steven; Forde, Susie; Qin, Xiao
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-2817
  Practice-Ready: Yes
• Identifying High Pile Rebound Soils Using Cone Penetrometer Pore Water Pressure Measurements: Case Studies in Central Florida
  Abstract: At certain depths during large diameter displacement pile driving, rebound well over 0.25 inch was experienced and followed by a small or zero set during each hammer blow. High pile rebound (HPR) soils may stop the pile driving and results in a limited pile capacity. The overburden depth at which HPR occurred is typically greater than 50 ft. In some cases, rebound leads to pile damage, delaying the construction project, and the requiring foundations redesign. HPR was evaluated at six Central Florida sites, during driving of square precast, prestressed concrete piles driven into saturated, fine silty to clayey sands and sandy clays. Pile Driving Analyzer (PDA) deflection versus time data, recorded during installation, was used to develop correlations between cone penetrometer (CPT) pore-water pressures, pile displacements and rebound. Fifteen CPT tests with pore-water pressure measurements (CPTu) were evaluated and comparisons were made to HPR from eleven piles at the six sites. At four sites where piles experienced excessive HPR with no or minimal set, the CPTu pore-water pressure yielded very high positive values of more than 20 tsf. However, at the site where the pile rebounded, followed by an acceptable permanent set, the measured CPTu pore-water pressure ranged between 5 and 20 tsf. The CPTu pore-water pressure exhibited values of less than 5 tsf at the site where no rebound was noticed. In summary, direct correlations between CPTu pore-water pressure and rebound were produced, which could be used to identify soils that produce HPR.
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi; Krajcik, Ryan
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi; Krajcik, Ryan
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2871
  Practice-Ready: Yes
• Influencing Sustainable Travel Intention Through Contextualized Presentation Format
  Abstract: Climate change is a global problem and transportation is a major contributor to it. In response to that problem, CO2 information on transport is being provided to the public to aid with informed decision-making. Choice experiments have found that CO2 mass information could influence choice, however, other research suggests that CO2 presented as mass is not fully understood and that the presentation of CO2 information affects interpretation. If a presentation format can affect understanding and interpretation, might it then affect intention (and choice) to perform sustainable travel? It can be argued that without information context, it would be difficult to interpret the appropriateness of CO2 information presented as mass. Information context, associated with alternative presentation formats, can highlight some aspects of the information to influence intention and choice, have it related to a societal goal, and could aid with analytical decision-making. If a format performs better in an analytical task, does it follow that it would have greater impact on influencing behavioral intention? Or might a format that includes emotional context result in stronger behavioral intention? This research examined how people’s behavioral intention responses for car use varied by three different contextualized formats (carbon budget, tree-equivalent, and earth-equivalent) in comparison to the information content format of simply CO2 mass.
  Authors: Waygood, E. Owen D.; Avineri, Erel
  Authors: Waygood, E. Owen D.; Avineri, Erel
  Year: 2013
  Document Type: Paper
  Subject: Energy; Environment
  Session: 503
  Paper Number: 13-2872
  Practice-Ready: Yes
• Evaluation of Texas Condition Assessment Program and Recommendations for Improvement
  Abstract: The Texas Department of Transportation (TxDOT) uses the Texas Condition Assessment Program (TxCAP) to measure and compare the overall road maintenance conditions among its 25 districts. TxCAP combines data from its three subsystems: the Pavement Management Information System (PMIS), which scores the condition of pavement; the Texas Maintenance Assessment Program (TxMAP), which evaluates roadside conditions; and the Texas Traffic Assessment Program (TxTAP), which assesses the condition of signs, work zones, railroad crossings, and other traffic elements. The scores for each of the subsystems are based on data of different sample sizes, accuracy, and levels of variations. Therefore, whether the use of the current TxCAP system is an effective and consistent means to measure the TxDOT roadway inventory conditions needs to be evaluated. Statistical analyses were carried out to evaluate the system from two aspects: 1) to determine whether the mechanism employed in TxCAP is effective in measuring the maintenance performance of 25 districts statistically, and 2) to determine whether the difference between the TxCAP scores for any two districts is statistically significant in terms of the insufficient sampling of the subsystems. A case study was carried out using sample data collected for the whole state from the year 2008 to 2010. The case study results show that the differences in scores between two districts are statistically significant for some of the districts and insignificant for some other districts. It is therefore recommended that TxDOT either compare the 25 districts by groups/tiers or increase the sample size of the data being collected if it wants to compare the districts as individual ones.
  Authors: Wu, Hui; Zhang, Zhanmin; Qazi, Abdus Shakur
  Authors: Wu, Hui; Zhang, Zhanmin; Qazi, Abdus Shakur
  Year: 2013
  Document Type: Paper
  Subject: Administration and Management; Maintenance and Preservation
  Session: 495
  Paper Number: 13-2850
  Practice-Ready: Yes
• Locating Traffic Sensors on a Highway Network: Models and Algorithms
  Abstract: We consider the problem of finding optimal sensor locations on a traffic network so as to characterize system use overall. We study the problem under two practical scenarios. In the first scenario, we assume there is a given number of sensors (p) that we need to locate on the highway network. In this context, the problem is to find a collection of p locations among a given collection of candidate locations. In the second scenario, we assume that there is a cost (ci) associated with installing a sensor at each candidate location i, and a total budget b. In this context, the problem is to find a collection of locations that provide the best possible characterization given the budget constraint. We propose a metric to evaluate a potential solution and then propose appropriate mathematical models for solving the problem for each scenario. We show that the budget-constrained problem is an extension of the well-known p-median problem. A new Lagrangian heuristic algorithm is presented to solve large instances of this problem where a budget constraint is imposed. Through a comprehensive computational experiment, we demonstrate that the Lagrangian heuristic algorithm provides solutions for large-scale networks within reasonable execution times. Examples are based on locating weigh-in-motion (WIM) sensors on a large-scale highway network.
  Authors: Sayyady, Fatemeh; Fathi, Yahya; List, George F.; Stone, John R.
  Authors: Sayyady, Fatemeh; Fathi, Yahya; List, George F.; Stone, John R.
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology; Operations and Traffic Management
  Session: 796
  Paper Number: 13-2853
  Practice-Ready: Yes
• Project Emissions Estimator (Pe-2): Tool to Aid Contractors and Agencies in Assessing Greenhouse Gas Emissions of Highway Construction Projects
  Abstract: Motivated by the need to address challenges of global climate change, this study develops and implements a project based life cycle framework that can be used to estimate the carbon footprint for typical construction work-items found in reconstruction, rehabilitation and Capital Preventive Maintenance (CPM) projects. Applying existing life cycle assessment methods and inventories, the proposed framework considers the life cycle emissions of products and processes involved in the raw material acquisition and manufacturing phase, and the pavement construction phase. It also estimates emissions due to vehicular use and maintenance operations during the service life of the pavements. An implementation of the framework is a web-based tool, the Project Emission Estimator (PE-2) that can be used to benchmark the CO2 footprint of highway construction projects. The research suggests ways of implementing PE-2 tool by contractors and state transportation agencies to benchmark and help reduce the CO2 footprint of highway construction projects.
  Authors: Mukherjee, Amlan; Stawowy, Brian
  Authors: Mukherjee, Amlan; Stawowy, Brian
  Year: 2013
  Document Type: Paper
  Subject: Design; Environment; Pavements
  Session: 705
  Paper Number: 13-2855
  Practice-Ready: Yes
• Electrical Resistivity Measurements in Cementitious Systems: Observations of Factors That Influence the Measurements
  Abstract: The electrical resistivity of concrete is increasingly measured as an indicator of its fluid transport properties, for use in quality control or for service life prediction. While electrical tests have the advantage of being easy and rapid to perform, there are several key factors that can influence the results including: 1) specimen geometry, 2) specimen temperature and 3) sample storage and conditioning. This paper addresses these issues and compares the measurements from several commercially available testing devices. First, the role of sample geometry is explained using three common geometries: surface, uniaxial and embedded electrodes. If the geometry is properly accounted for, measurements from different test geometries result in electrical resistivity values that are similar. Second, the role of sample temperature is discussed for both pore solution and bulk tests on cylinders. Third, the paper examines the importance of sample curing, storage and conditioning. Sample storage and conditioning influences both the degree of hydration and the degree of saturation. The role of sample volume to solution volume is discussed as this may influence alkali leaching. This paper is intended to identify factors that influence the results of the rapid electrical test measurements and to help identify areas of future research that are needed so that robust specifications and standard test methods can be developed. This will enable electrical tests to be used to provide rapid, accurate, repeatable measurements of concrete’s electrical properties.
  Authors: Spragg, Robert; Villani, Chiara; Snyder, Kenneth; Bentz, Dale P.; Bullard, Jeffrey; Weiss, William Jason
  Authors: Spragg, Robert; Villani, Chiara; Snyder, Kenneth