2013 Session: 494

• Evaluation of Impacts of Share the Road Sign on Driver Behavior Near Bicyclists
  Abstract: The interaction of motorists and bicyclists, particularly during passing maneuvers, is an area of concern to the bicycle safety community as there is a general perception that motor vehicle drivers often do not share the road effectively with bicyclists. One potential countermeasure to address this concern is the use of a bicycle warning sign with a “Share the Road” plaque. This paper presents the results of a controlled field evaluation of this treatment, which involved an examination of driver behavior while passing bicyclists. A series of field studies were conducted concurrently on two segments of a high-speed, rural two-lane highway. These segments were similar in terms of roadway geometry, traffic volumes, and other relevant factors, except that one segment included centerline rumble strips while the other did not. A before-and-after study design was utilized to examine changes in motor vehicle lateral placement as they relate to the presence of the sign treatment. The signs were found to reduce the proportion of motor vehicles that passed bicyclists in the central lane position, providing evidence that the sign is effective in shifting motor vehicles away from the right edge of the travel lane. However, the sign treatment did not significantly affect the physical buffer distance between the bicyclists and passing motorists or the proportion of motor vehicles that crowded bicyclists as they passed. Vehicle type, bicyclist position, and the presence of centerline rumble strips or opposing traffic were also found to affect lateral placement during passing maneuvers.
  Authors: Kay, Jonathan; Savolainen, Peter Tarmo; Gates, Timothy J.
  Authors: Kay, Jonathan; Savolainen, Peter Tarmo; Gates, Timothy J.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0164
• Modeling Impacts of Access Design and Spatial Pattern on Crash Risks of Pedestrians and Bicyclists on Urban Multilane Highways in Florida
  Abstract: This paper presents a study on the impacts of access design and spatial pattern on the risk of pedestrian and/or cycling crashes at access points on urban multilane highways. Two prediction models, using negative regression and logistic regression, were developed to evaluate the impacts in terms of crash frequency and injury severity respectively. For developing the models, crash records were collected at 153 access points with different access designs for a period of 4 years (2007-2010) on the state roads in Florida.Results of this study show that, four-leg access point with directional median opening is most likely to increase the frequency of pedestrian/bicycle crashes at access points than other access designs at all spatial locations. Inner lanes experience the most pedestrian/bicycle crashes, followed by side roads (SR) and outside lanes (TO) for all access types. Three-leg access point with closed median opening and three-leg access point with full median opening experience a higher injury risk if a pedestrian/bicyclist crash occurs at an access point. Medians and inner lanes experience the highest injury risk if a pedestrian/bicyclist crash occurs at an access point. Middle lanes, outside lanes, left turn bays, crossing walks are more likely to increase injury severity of pedestrian/bicycle crashes than road side, side roads, and auxiliary lanes. In terms of crash occurrence, the top “dangerous” points are inner lanes, side roads, and outside through lanes with the access design of four-leg access point with directional median opening. In terms of injury severity, the top “dangerous” points are medians with any access design and inner lanes with the access designs of three-leg access point with closed or full median opening. Based on the results, suggested countermeasures for improving pedestrian/bicyclist safety at access points were provided.
  Authors: Wang, Zhenyu; Lin, Pei-Sung; Chen, Hongyun; Lu, Jian John; Deng, Weiping
  Authors: Wang, Zhenyu; Lin, Pei-Sung; Chen, Hongyun; Lu, Jian John; Deng, Weiping
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0386
• Bicycle-Specific Traffic Signals: Results from State-of-the-Practice Review
  Abstract: This paper presents the results of a survey of North American jurisdictions with known installations of bicycle-specific traffic signals and a review of available related engineering guidance. Surveys were sent out to agencies in twenty-three jurisdictions (twenty-one in the United States and two in Canada) that requested detailed engineering aspects of the signal such as placement, mounting height, lens diameter, backplate color, type of actuation, interval times, use of louvers, and performance. A total of 63 intersections and 149 separate signal heads are included in this paper. The results of the survey highlighted variety in several design elements utilized by agencies when implementing bicycle signals. This variety might impact cyclist and motorist comprehension as well as the ability to utilize the bicycle signal head in a variety of intersection configurations. A subsequent review of the guidance documents available to engineers and planners revealed generally consistent guidance with regard to the design of bicycle-specific traffic signals. The generation of guidance on bicycle signals as grown substantially in recent years and, given the accelerated deployments of bicycle-specific signals themselves, it is likely that there will be less variety in future designs.
  Authors: Thompson, Sara; Monsere, Christopher M.; Figliozzi, Miguel
  Authors: Thompson, Sara; Monsere, Christopher M.; Figliozzi, Miguel
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0536
• Cyclist Behavior on Exclusive Bike Path: Longitudinal Analysis
  Abstract: With the rapid increase of bicycle modal share in North America, the need for more refined models arises in order to capture and model cyclist behaviour on bike facilities.Hence, this paper presents a comparison of a set of six bike-following models. The results of these models was compared to real world data collected with a GPS devices for a pair of cyclists in a following situation without opportunity to overtake. The paper presents also some finding on fundamental relationships using data collected by video at a fixed location on a bike facility. Finally, the paper presents a behavioural comparison between the bike-cyclist and the car-driver systems.The analysis and the results indicate that both bike-following models and fundamental relationships present interesting potentials to reproduce real world data given additional data.
  Authors: Manar, Abdelaziz; Desmarais, Jean-Philippe
  Authors: Manar, Abdelaziz; Desmarais, Jean-Philippe
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0699
• Novel Approach for Diagnosing Cycling Safety Issues Using Automated Computer Vision Techniques
  Abstract: The use of traffic conflicts for safety diagnosis has been gaining acceptance as a surrogate for collision data analysis as they provide insight into the failure mechanism that leads to road collisions. This paper demonstrates an automated proactive safety diagnosis approach for cycling safety using video-based computer vision techniques. Traffic conflicts are automatically detected and conflict indicators such as Time to collision (TTC) are calculated based on the analysis of the road-user positions in space and time. Additionally, non-conformance of vehicles to travel regulations; specified as failure to respect yielding signage at the intersection are identified. The procedure is applied for the safety analysis of a newly installed bike lane at the southern approach of a major Bridge (Burrard Bridge) in Vancouver, British Columbia. The results showed a high exposure of cyclists to traffic conflicts. Vehicle conflicts at the location were also identified and analyzed. Practical solutions to address the safety issues at the location were presented. The proposed approach overcomes shortcomings with reliance on collision data and the manual observations of traffic conflicts.
  Authors: Sayed, Tarek; Zaki, Mohamed H.; Autey, Jarvis
  Authors: Sayed, Tarek; Zaki, Mohamed H.; Autey, Jarvis
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0744
• Integration of GPS Traces and Digital Elevation Maps for Improving Bicycle Traffic Simulation Behavior
  Abstract: In order to take in consideration bicycle traffic in realistic simulation, one should consider more than a simple approach based on overall average speed and acceleration. There are several different factors that should be considered, such as the diversity of people's fitness that ride bicycles on the road, the way speed varies along segments and more importantly how terrain slope influences rider's behavior.In this paper we present our approach for simulating bicycle traffic using real GPS data as source for enhancing simulation. We discuss the specific details related to the analysis process performed on a set of bicycle commuting traces, as well as the development of a custom driver behavior for VISSIM that uses statistic data taken from those bicycle GPS traces. We also propose a new methodology for considering the way slope affects bicycle traffic, as this is one of the most relevant factors related to bicycle riding.
  Authors: Henriques, Norberto; Bento, Carlos
  Authors: Henriques, Norberto; Bento, Carlos
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1421
• Bicycle Route Choice Model That Incorporates Distance and Perceived Risk
  Abstract: In this study, we have developed a procedure to estimate bicycle link cost function parameters for use in a bicycle route choice model. A practical estimation procedure was established by formulating a bi-level optimization problem. Based on bicycle commuters’ revealed preference route choices to a university campus, a linear function with an interaction cost term was found to be the best model specification. Other models that incorporated both distance and risk terms were almost as good. Model forms that used only distance or only risk were clearly inferior, indicating the importance of using both factors. In order to investigate the relative importance of travel distance and risk concern, an elasticity ratio test was conducted. The results indicate that, for our database, travel distance is more important in route choice decisions. However, when perceived risk, as represented by link Bicycle Compatibility Index, reaches high levels, the role of the risk factor in bicycle route choice becomes almost as important as the distance factor. Bicyclists are then more likely to trade off increased distance for decreased perceived risk. The bi-level optimization method described in this paper provides a practical way to approximate bicyclist route choice behavior using a simple measure (distance) and the well-recognized Bicycle Compatibility Index. The resulting model can guide investments in bicycle facilities.
  Authors: Kang, Lei; Fricker, Jon D.
  Authors: Kang, Lei; Fricker, Jon D.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1677
• Is Scientific Evidence in Practice? Review of Driver and Cyclist Education Materials with Respect to Cycling Safety Evidence
  Abstract: Introduction: Countries with high cycling rates have national, school-based, mandatory cycling education programs whereas in North America cycling education is diverse and disparate. The aim of this research was to understand what cycling safety content is delivered in Canadian jurisdictions and how training materials align with scientific evidence.Methods: Cycling safety literature was reviewed and cycling education materials were compiled from drivers’ licensing and cyclist education programs. The education materials were compared with the evidence to determine where there were agreements, disagreements or gaps. Results: 56 scientific articles focused on crash or injury risk, injury severity, or other safety outcomes and met our inclusion criteria. The evidence covered bicycling operations, visibility and safety gear, road characteristics, route types, and bicycle-motor vehicle interactions. 48 training materials for cyclists and/or drivers were gathered from 12 provincial and territorial driver’s licensing jurisdictions, 5 municipalities, and 7 advocacy organizations. Broadly, the materials covered topics of bicycle fit and maintenance, rules of the road, in addition to the topics included in the safety literature. Some of the education items were supported by evidence, although many were related to legislation or common sense. Evidence on motor vehicle passing distances conflicted with the guidance about where to cycle on the road. A gap in the educational materials was the relative safety of different route infrastructure, important for route planning.Conclusions: This research illustrates the diversity of cycling education in Canada and suggests areas where education materials could be modified to align with scientific evidence on safe cycling.
  Authors: Winters, Meghan; Weddell, Angie; Teschke, Kay
  Authors: Winters, Meghan; Weddell, Angie; Teschke, Kay
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1534
• Analyzing Bicyclists’ Choices of Bicycle Facility Type Using a Random-Parameter Probit Model
  Abstract: When allocating limited funds to bicycle facilities, it would be helpful to know the extent to which a new facility will be used. If a bicycle lane is added to a street, how many bicyclists will no longer use the sidewalk? If a separate bicycle path is constructed, how many bicyclists will move from the street or sidewalk? Bicyclists were interviewed at the end of their trips and asked which part of the cross-sections along their routes they had used – on-street or off-street. This study developed a random-parameter probit model to analyze the bicyclists’ facility preferences and capture the unobserved heterogeneity across the population. This model was found to be superior to a standard binary probit model and a random effects model. Sidewalk width, traffic signals, segment length, road functional class, street pavement condition, and one-way street configuration were found to be statistically significant. The compound effects of multiple variables were demonstrated by varying sidewalk width and Bicycle Compatibility Index. The results suggest that merely adding a bicycle lane does not guarantee that a significant proportion of bicyclists will switch to it. Lessons also can be drawn from marginal effects and elasticity to indicate where a particular bicycle facility would be most compatible with bicyclists’ revealed choices.
  Authors: Kang, Lei; Fricker, Jon D.
  Authors: Kang, Lei; Fricker, Jon D.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1676
• Evaluating Bicycle Infrastructure: Assessment of Three Alternative Quality-of-Service Metrics
  Abstract: Cities throughout the United States are increasingly interested in designing bicycle facilities to attract new riders and improve the comfort of existing riders. In particular, transportation agencies increasingly use treatments such as cycle tracks, buffered bike lanes, and colored pavement to supplement or replace traditional facilities (e.g., bike lanes). To respond to this trend, transportation professionals require evaluation metrics that effectively assess design options and provide decision-support in choosing bicycle facilities that best match local context. Recent research has produced several bicycle evaluation tools (e.g., bicycle Level of Service) that attempt to fill this need. This paper presents the results of a comprehensive real-world comparison of three leading bicycle evaluation tools: 2010 Highway Capacity Manual Bicycle Level of Service (BLOS); Danish Road Directorate BLOS; and San Francisco's Bicycle Environment Quality Index (BEQI). Each evaluation tool was applied to a before-after evaluation of two bicycle facility installations in Washington, DC. The tools were assessed using a consistent set of evaluation criteria including: data and time requirements; sensitivity to key inputs; intuitiveness of the results; and soundness of the tool’s theoretical basis. Intercept surveys of facility users were used to compare the tool outputs to actual user preferences. Results suggest several shortcomings with the HCM BLOS methodology that make it unsuited to assessing bicycle design options that include cycle tracks and other emerging bicycle facility types. Additional research is needed to develop a nationally accepted bicycle evaluation tool to reflect the growing variety of bicycle facilities in the United States.
  Authors: Parks, Jamie; Tanaka, Alison; Ryus, Paul; Monsere, Christopher M.; McNeil, Nathan Winslow; Goodno, Mike
  Authors: Parks, Jamie; Tanaka, Alison; Ryus, Paul; Monsere, Christopher M.; McNeil, Nathan Winslow; Goodno, Mike
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-2191
• A Methodology to Estimate Bicyclists’ Acceleration and Speed Distributions at Signalized Intersections
  Abstract: As cities across North America install new infrastructure to accommodate a growing number and variety of bicyclists, installation of bicycle-specific traffic signals is a common design element. A recent survey has shown that there is there is a lack of consistency in their design and timing. In particular, minimum green signal timing is highly dependent on the assumed acceleration and speed performance of bicyclists’ but there is no detailed methodology to estimate these performance values. However, recent AASHTO, Caltrans, and NACTO documents require that an adequate clearance interval shall be provided and that in determining this minimum interval field investigation of bicyclists’ speeds is recommended. Furthermore, even if detailed video trajectories are available, the determination of a value for field speed and acceleration is not trivial because values of speeds and accelerations are a function of time and individual bicyclist performance. The purpose of this research is to develop and apply a general methodology to estimate bicyclists’ acceleration and speed for traffic signal timing applications. Utilizing physical equations of motion, this research analytically derives expressions that can be used to classify individual bicyclist’s performance as function of the observed acceleration profile. The analysis indicates that four basic acceleration profiles are possible and the profiles can be obtained using a parsimonious field data collection method. The methodology is successfully applied to two intersections in Portland, Oregon. A detailed statistical analysis of the results shows that the results are intuitive and that the methodology successfully categorizes bicyclists’ performance variations due to topography or demographic characteristics.
  Authors: Figliozzi, Miguel; Wheeler, Nikki; Monsere, Christopher M.
  Authors: Figliozzi, Miguel; Wheeler, Nikki; Monsere, Christopher M.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-2697
• Impact of Bicycle Boxes on Safety of Cyclists: Case Study in Montreal, Canada
  Abstract: This paper presents a methodology to evaluate the effectiveness of a bicycle treatment (bike boxes) at intersections using a before-after surrogate safety analysis based on longitudinal video-data analysis. As a surrogate safety measure, cyclists’ red-light violations are quantified for two periods before and two periods after the installation of a bicycle box at a signalized intersection in Montreal. For this purpose several hours of video were collected before and after the installation of the treatment. Based on the video data, red-light violations and potentially associated factors were collected for each cyclist that crossed the intersection, such as sex, age, group size, use of helmet, whether a cyclist stopped before crossing, vehicle-cyclist gap, etc. Violations with a short vehicle-cyclist gap were classified as dangerous (i.e., those situations in which cyclists pass the intersection during the red phase with a small vehicle gap). For the data analysis, a multinomial logit regression technique was used to identify the factors that increase or decrease the probability of cyclist violations as well as their changes over time. Both raw estimates and model estimates show that the presence of a bicycle box has a significant impact on the total number of cyclists’ violations; however, the impact on the number of dangerous violations is not clear. More video data from other intersections before and after the treatment implementation is required to validate these preliminary conclusions. Moreover, the video-data generation and surrogate approach proposed here can be applied to the evaluation of other bicycle treatments.
  Authors: Zangenehpour, Sohail; Miranda-Moreno, Luis Fernando; Saunier, Nicolas
  Authors: Zangenehpour, Sohail; Miranda-Moreno, Luis Fernando; Saunier, Nicolas
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-2909
• Operational Analysis of “Sharrows” on Roadways with Narrow Lane Widths
  Abstract: Sharrows are intended to encourage shared use of a facility for both bicycles and motor vehicles, as well as indentify the appropriate placement for bicyclists within the roadway. This paper analyzes the influence of several site characteristics on the operational and safety effects on bicyclists and motorists at two curbed roadway segments in Florida. Three main site variables were studied: lateral separation between vehicles and bicyclists, vehicle encroachments to the adjacent inside lane, and distance from face of curb that bicyclists track. Results suggest that installation of sharrows can increase the lateral vehicle clearance significantly. It was also observed that less restrictive lane changing conditions greatly increase the lateral separation between vehicles and bicyclists. Also, the percentage of vehicles that passed along side bicyclists with little to no encroachment was notably reduced after sharrows were placed, suggesting positive safety effects for bicyclists. Overall, operational effects for bicyclists and motor vehicles were positive with the implementation of sharrows.
  Authors: Sando, Thobias; Angel, Michelle; Hunter, William Wesley; Chimba, Deo; Kwigizile, Valerian
  Authors: Sando, Thobias; Angel, Michelle; Hunter, William Wesley; Chimba, Deo; Kwigizile, Valerian
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-2507
• Influence of Bridge Facility Attributes on Bicycle Travel Behavior
  Abstract: This paper develops an unlabeled multinomial logit model to estimate the impact bridge facility attributes have on bicycle travel behavior. The data used to estimate the model was collected May through October 2011 in Austin, Texas via a GPS-based smartphone application that allowed trips to be tracked in real-time. Demographic (age, gender, and cycle frequency) and trip purpose information was also collected. Three attributes are analyzed in the model: bridge accessibility/connectivity to the bicycle network, vehicular volume, and bicycle separation from traffic. Accessibility and bicycle separation significantly impacted bicyclists’ behavior, especially for comfort-prone users (female and infrequent bicyclists) as well as for trips where travel time is not a significant issue. Distance was found to be the most significant factor, particularly for time-constrained trips (trips during the peak period and commute trips). Distance was less important for recreational trips as well as for female bicyclists.
  Authors: Melson, Christopher L.; Duthie, Jennifer; Boyles, Stephen
  Authors: Melson, Christopher L.; Duthie, Jennifer; Boyles, Stephen
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-3358
• Associations Between Road Network Structure and Pedestrian-Bicyclist Accidents
  Abstract: It is widely known that the road network layout can impact the non-motorized users’ traffic safety by changing the non-motorized traffic volume and road users’ behavior. Different road network patterns lead to different traffic safety levels for non-auto users and a single pattern can even have both the safe and unsafe features at the same time. By knowing what features can lead to safer traffic environment, existing road networks can be improved and new network patterns can be produced by combining all safe features from different patterns. Therefore, the associations between road network structure and pedestrian-bicyclist crashes are analyzed in this paper to determine how the structural features of a road network affect non-motorist safety. Three structural measures including average geodesic distance, network betweenness centrality, and overall clustering coefficient are calculated based on the road networks of 321 census tracts in Alameda County, California. Then the three measures together with other factors like traffic behavior, land use, transportation facility, and demographic features are employed separately in a spatial statistical model called geographically weighted regression. Conclusions are: if a network is more highly centered on major roads, there will be fewer non-motorist crashes; the network which has more average number of intersections between each pair of roads tends to have fewer accidents for pedestrians and bicyclists; and, the more a network is clustered into several sub-core networks, the lower the non-motorist crash count will be.
  Authors: Zhang, Yuanyuan; Bigham, John M.; Li, Zhibin; Ragland, David R.; Chen, Xiaohong
  Authors: Zhang, Yuanyuan; Bigham, John M.; Li, Zhibin; Ragland, David R.; Chen, Xiaohong
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-4316
• Characteristics of Multimodal Conflicts in Urban On-Street Bicycle Lanes
  Abstract: In urban areas, bicycles traveling in bicycle lanes encounter a variety of obstructions, including pedestrians and various types of motor vehicles. While previous studies have focused on identifying the frequency of such events, the goal of this study is to characterize these conflicts. In order to evaluate specific characteristics that may influence the frequency of specific conflict types, including bicycle lane designs, curb regulations, and land uses, field data collection was performed in the Manhattan and Brooklyn boroughs of New York City. This paper describes a method for evaluating the frequency of conflicts between bicycles traveling in on-street bicycle lanes and various other transportation modes, and for identifying factors that may impact these frequencies .
  Authors: Conway, Alison J.; Cheng, Jialei; Peters, Diniece; Lownes, Nicholas E.
  Authors: Conway, Alison J.; Cheng, Jialei; Peters, Diniece; Lownes, Nicholas E.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-4545
• Automated Analysis of Cyclist Crossing Speed: Validation and Investigation of Influencing Factors
  Abstract: This study investigates the use of an automated video analysis technique to calculate cyclist speed. The proposed technique enables the automated observation of large volume of naturalistic cyclist movements in a resource-efficient manner. Video data was collected for a total of 190 hours at a busy intersection in the Downtown area of Ottawa. Observations were distributed over the Fall and Summer seasons. Video subsequences were identified in which crossing was performed by one or more cyclists. Automated tracking was performed to record the sequence of positions which cyclists occupy while traversing an intersection. Extensive validation work was performed. The first validation experiment relied on the measurement of actual cyclist paths based on following the trace of bike tires to estimate average crossing speed. The second validation task utilized cyclist tracks which moved reasonable matched paths with measured lengths. The total number of crossing events in the first task was 16 and in the second task was 482. The average percentage of absolute difference between measured and actual speed for the first task was 5.22% and 4.98% for the second task. Statistical analysis was conducted to investigate the effect of different factors on average crossing speed and the error in speed measurement. Several observations are reported regarding patterns of tracking errors and recommendations are made for future improvements.
  Authors: Kassim, Ali; Ismail, Karim; Abd El Halim, Halim Omar
  Authors: Kassim, Ali; Ismail, Karim; Abd El Halim, Halim Omar
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-4879
• Assessing the Completeness of Bicycle Trail and Designated Lane Features in OpenStreetMap for the United States and Europe
  Abstract: This paper assesses the completeness of OpenStreetMap data for cycling features, in particular bicycle trails and designated lanes, for selected cities in the United States and Europe. While most available comprehensive road network datasets, either from commercial data vendors or public agencies, are tailored towards motorized traffic, OpenStreetMap as a community based, open access platform for geospatial vector data provides a viable alternative for data retrieval of cycling feature data. The analysis in this study reveals a steady growth of cycling related data in the OpenStreetMap platform over the past few years, rendering the data more complete and appropriate to be used as base map for planning studies on non-motorized transportation. A comparison with the Google Maps Bicycling layer shows that the data quality of OpenStreetMap designated lanes is particularly high. OpenStreetMap bicycle trail data are somewhat more erroneous through missing data and incorrectly classified trails, however still of relatively good quality. For practical purposes it is recommended to check OpenStreetMap trail data against the Google Maps Bicycling layer before an analysis is conducted based on OpenStreetMap trail data.
  Authors: Hochmair, Hartwig; Zielstra, Dennis; Neis, Pascal
  Authors: Hochmair, Hartwig; Zielstra, Dennis; Neis, Pascal
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-5099
• 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
• 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
• Dissecting Perceived Traffic Risk as a Barrier to Adult Bicycling
  Abstract: Nearly twenty years of federal policy has sought to increase bicycling trips to improve physical health, mitigate automobile pollution, and increase access–but research shows that people’s concerns regarding the risk of bicycling near traffic remain a significant barrier to widespread cycling. While an important finding, the research has not disaggregated “traffic risk” to expose its many aspects and how they may affect bicyclists with differing skill levels, experiences, and behaviors. This paper elaborates on results from a recent internet survey examining various aspects of traffic risk among 579 non-bicycling drivers, bicycling drivers, and non-driving bicyclists in the Bay Area. Analysis of variance tests revealed that bicyclists’ perceptions of danger differed according to riding frequency, with frequent cyclists more likely to fear more commonly reported crash types, while potential cyclists feared crashes that occur less frequently. In addition, an “exposure effect” seemed to appear such that those who bicycle occasionally reported the most fear of all bicyclists. Respondents also reported “near miss” experiences with motor vehicles. Nearly 70% of bicyclists in the sample have experienced a “near miss”, and 14% reported being hit. The data indicate that perceptions of traffic risk are related to near miss and crash experiences, although this differed according to bicycling frequency. These findings suggest that efforts targeting specific driver and bicyclist behaviors associated with these “near misses” could mitigate perceived traffic risk for bicyclists.
  Authors: Sanders, Rebecca L.
  Authors: Sanders, Rebecca L.
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-5264
• 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
• A New Approach in the GIS Bikeshed Analysis with Consideration of Topography, Street Connectivity, and Energy Consumption
  Abstract: In recent years, bike planning has garnered attention from planners and the public as a sustainable mode of transportation and as a means to exercise and reduce health risks. In addition, following the success of bike-share programs in cities in Paris and Lyon, France, and Montreal, Canada, and several US cities initiated similar programs. With this background, GISs have been applied to conduct a spatial analysis and produce heat maps of bike-travel demand and suitable areas for a bike-sharing program. These studies include a variety of factors, such as demographics of residents, land use, street types, and available bike facilities and transit services. However, there have been few studies that take topography and street connectivity into account. The study proposes a method to combine topography and presence of intersections with estimates of energy used to bike, and incorporate the resulting travel-impedance factor, as well as street connectivity, into a GIS analysis. Using the case in Montgomery County, Maryland, USA, where elevation and street connectivity varies substantially among neighborhoods, this study shows how the size and shape of bikesheds originating from proposed light rail stations vary in the GIS analysis with or without taking into account these critical factors. The analysis results have significant implications for various bike planning programs using a GIS analysis.
  Authors: Iseki, Hiroyuki; Tingstrom, Matthew
  Authors: Iseki, Hiroyuki; Tingstrom, Matthew
  Year: 2013
  Document Type: Paper
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1774
  Practice-Ready: Yes
• Cyclist Behavior on Exclusive Bike Path: Longitudinal Analysis
  Authors: Desmarais, Jean-Philippe
  Authors: Desmarais, Jean-Philippe
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0699
• Integration of GPS Traces and Digital Elevation Maps for Improving Bicycle Traffic Simulation Behavior
  Authors: Henriques, Norberto
  Authors: Henriques, Norberto
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1421
• Is Scientific Evidence in Practice? Review of Driver and Cyclist Education Materials with Respect to Cycling Safety Evidence
  Authors: Winters, Meghan
  Authors: Winters, Meghan
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1534
• A New Approach in the GIS Bikeshed Analysis with Consideration of Topography, Street Connectivity, and Energy Consumption
  Authors: Tingstrom, Matthew
  Authors: Tingstrom, Matthew
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-1774
• Evaluating Bicycle Infrastructure: Assessment of Three Alternative Quality-of-Service Metrics
  Authors: Tanaka, Alison
  Authors: Tanaka, Alison
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-2191
• Associations Between Road Network Structure and Pedestrian-Bicyclist Accidents
  Authors: Zhang, Yuanyuan
  Authors: Zhang, Yuanyuan
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-4316
• Characteristics of Multimodal Conflicts in Urban On-Street Bicycle Lanes
  Authors: Conway, Alison
  Authors: Conway, Alison
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-4545
• Modeling Impacts of Access Design and Spatial Pattern on Crash Risks of Pedestrians and Bicyclists on Urban Multilane Highways in Florida
  Authors: Wang, Zhenyu
  Authors: Wang, Zhenyu
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0386
• Network Connectivity and Low-Stress Bicycling
  Authors: Mekuria, Maaza
  Authors: Mekuria, Maaza
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-0427
• Influence of Bridge Facility Attributes on Bicycle Travel Behavior
  Authors: Melson, Christopher
  Authors: Melson, Christopher
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Design; Pedestrians and Bicyclists; Safety and Human Factors
  Session: 494
  Paper Number: 13-3358