2013 Session: 423

• Quantifying Road Grade Based on In-Vehicle Measurements with Global Positioning System Receivers
  Abstract: Variability in real-world vehicle fuel use and emissions during a trip depends primarily on vehicle speed, acceleration, and road grade. However, there is not a standard method for measuring road grade from a moving vehicle. Changes in road grade of more than a percentage point significantly affect fuel use and emission rates. Consumer grade Global Positioning System receivers with barometric altimeter (GPS/BA) are used to measure position and elevation. Data were collected from 12 vehicles, each using 3 GPS receivers, for a total of 36 repeated GPS/BA runs on eight one-way routes in the Research Triangle Park, NC region. Road grade was estimated by combining data from 9, 18, and 36 runs and applying linear regression to non-overlapping and adjacent road segments of length d. The accuracy of the estimated road grade was evaluated based on comparison to estimates from aircraft-based LIDAR measurements. The average grade is found to be accurate. The average precision is 0.39, 0.25, and 0.16 percentage points, for sample sizes of 9, 18, and 36 runs, respectively, among 1,116 individual road segments. The proportion of segments that have road grade precision within a target of +/-0.5 percentage points are 80 percent for 9 runs, 98 percent for 18 runs, and 99.8 percent for 36 runs. Thus, the use of a low cost GPS/BA is a promising approach for accurate and precise measurement of grade relative to data quality needs for quantifying variability in fuel use and emissions.
  Authors: Yazdani Boroujeni, Behdad; Frey, H. Christopher
  Authors: Yazdani Boroujeni, Behdad; Frey, H. Christopher
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-1417
• Enhanced Analysis of Crashes in the Proximity of Work Zones Through Integration of Statewide Crash Data with Lane Closure System Data
  Abstract: Highway work zones interrupt regular traffic flow and lead to safety concerns. Comprehensive knowledge of the crashes and work zones is essential to identify the risk factors. The Wisconsin Lane Closure System (WisLCS), a scheduling and reporting system for highway lane closures statewide, provides a new opportunity to match crashes to specific work zones on a system-wide level. This study conducts an analysis of the safety risks in the proximity of work zones. The WisLCS and the MV4000 Crash Data Retrieval Facility, both part of the WisTransProtal system at the University of Wisconsin-Madison TOPS Laboratory, provide the necessary data for this study. A matching algorithm is used to relate reported work zone crashes with the corresponding work zones, which relies on a common underlying linear referencing system used in the two data systems. Based on the results, it is clear that work zones cause safety concerns outside of the physical boundaries (upstream and downstream) and scheduled time periods (before and after the reported operation hours). In some scenarios, those crashes occurring outside of work zones even have a higher risk of overall and severer injury. Some suggestions are also made based on the findings to improve work zone safety and enhance work zone reporting monitoring in the future. Although developed based on the systems in Wisconsin, the general ideas of this study can also be applied to similar information systems.
  Authors: Cheng, Yang; Parker, Steven; Ran, Bin; Noyce, David A.; Szymkowski, Rebecca
  Authors: Cheng, Yang; Parker, Steven; Ran, Bin; Noyce, David A.; Szymkowski, Rebecca
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-3359
• 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
• 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
• 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
• 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
• Using Geographic Information Systems to Develop an Intersection Inventory for Safety
  Abstract: In 2010, there were 30,196 fatal crashes, 23 percent of which were intersection or intersection-related. One of the major challenges transportation agencies face when trying to address intersection safety is not having a sufficient enough intersection inventory that provides information on the location, operations, or geometrics of the intersections. The goal of this paper is to demonstrate how agencies can use readily available tools, such as geographic information systems (GIS), and existing transportation datasets to develop a base intersection inventory. This paper will also demonstrate how an agency can conduct a more robust data collection effort by expending only a little more resources. This is based on an effort conducted for the New Hampshire Department of Transportation (NHDOT) to build an intersection inventory of 10,300 intersections. The Federal Highway Administration (FHWA) funded this effort as part of a project to demonstrate the feasibility of collecting Model Inventory of Roadway Elements (MIRE) data and incorporating them into an agency’s safety program.
  Authors: Lefler, Nancy X.
  Authors: Lefler, Nancy X.
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-4663
  Practice-Ready: Yes
• Conflation Methodologies to Incorporate Consumer Travel Data into State HPMS Data Sets
  Abstract: The objectives of this study were to evaluate the feasibility of using private sector speed data to generate performance measures in Kentucky. These measures can be used to annually facilitate congestion management and travel model improvements by creating a mechanism to integrate commercially available speed data into Kentucky’s existing transportation network. Also, due to the large number of records in these databases, this research identified methods to effectively display data to state and metropolitan planning organization (MPO) employees to maximize the benefit of its use.This research helped to coordinate the purchase of two datasets: 2010 analytical traffic pattern data on the Traffic Message Channel (TMC) network in Kentucky and a more complete 2011 link-based network which included a broader coverage. Both data sets included average speeds, probe counts, and the standard deviation for each time interval for various time periods.In order for these datasets to be useful to state and local agencies, they were conflated with Kentucky’s existing highway network. Both of the datasets were linked to networks that differ from the state’s Highway Performance Monitoring System (HPMS) network. There is a need to link the purchased data to the state’s network as it contains attributes critical in developing performance measures.The usefulness of the private sector speed data relied greatly on the success of the conflation process with the state’s HPMS data. In order to derive performance measures from the data, several state-owned attributes were needed (such as traffic volumes and highway type). It was found that the TMC network provided more reliable descriptive statistics as compared to the link-based network which used free-flow speeds in records with no probe data. Free-flow speeds are useful as a secondary estimate for travel times for navigation, but not for performance measures. Conversely, the coverage of the link-based network was significantly more prominent than that of the TMC-network.
  Authors: Green, Eric R; Ripy, John; Chen, Mei; Zhang, Xu
  Authors: Green, Eric R; Ripy, John; Chen, Mei; Zhang, Xu
  Year: 2013
  Document Type: Paper
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-4682
  Practice-Ready: Yes
• Automatic Network-Level Identification of Sight Distance Values from Existing Data Sets
  Authors: Santiago-Chaparro, Kelvin
  Authors: Santiago-Chaparro, Kelvin
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-0054
• Conflation Methodologies to Incorporate Consumer Travel Data into State HPMS Data Sets
  Authors: Green, Eric
  Authors: Green, Eric
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-4682
• Feasibility and Advantages of Estimating Local Road VMT Based on GPS Travel Data
  Authors: He, Xiang
  Authors: He, Xiang
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Data and Information Technology
  Session: 423
  Paper Number: 13-2402