2013 Session: 454

• Cyclist Injury Severity in a Cycling Nation: Evidence from Denmark
  Abstract: Denmark is one of the leading cycling nations, where cycling trips constitute a large share of the total trips and cycling safety assumes a top priority position in the agenda of policy makers. The current study investigates the risk factors associated with cyclist injury severity on Danish roads by examining a comprehensive set of accidents involving a cyclist and a third party between 2007 and 2011. The current study estimates a generalized ordered logit model of cyclist injury severity because of its ability to accommodate the ordered-response nature of severity while relaxing the proportional odds assumption. Model estimates and average pseudo-elasticities illustrate that cyclist injury severity is positively related to (i) elderly cyclists over 60 years of age, (ii) cyclist intoxication, (iii) conflicts between cyclists going straight or turning left and other vehicles going straight, (iv) speed limits above 70-80 km/h, (v) slippery road surface, (vi) road sections, and (vii) heavy vehicle involvement. Moreover, model results show that cyclist injury severity is negatively related to (i) helmet use, (ii) the availability of cycling paths, (iii) dense urban development, possibly due to the ‘safety in numbers’ phenomenon.
  Authors: Kaplan, Sigal; Vavatsoulas, Konstantinos; Prato, Carlo Giacomo
  Authors: Kaplan, Sigal; Vavatsoulas, Konstantinos; Prato, Carlo Giacomo
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-1547
• Bicyclists’ Injuries and the Cycling Environment: Impact of Route Infrastructure
  Abstract: Introduction. Safety concerns have contributed to low bicycling rates in North America. Injury rates are lower and cycling is more common in northern European countries where route infrastructure is designed for cyclists, yet few studies have examined the relationship between the cycling environment and injuries.Methods. 690 people injured while cycling were recruited via emergency departments in Toronto and Vancouver, Canada. Conditional logistic regression compared route infrastructure at each injury site to that of a randomly selected control site from the same trip. The case-crossover design controlled for exposure to risk and for personal characteristics and other factors that are stable within a trip.Results. Of 15 route types, cycle tracks (physically separated paths alongside city streets) had the lowest risk, about 9 times lower than the reference (arterials and collectors with parked cars and no bike infrastructure). Bike lanes on arterials and collectors with no parked cars, local streets, and off street bike paths had 2-fold risk reductions. Risks on arterials and collectors were lower when parked cars were not present. Other infrastructure characteristics were associated with increased risks: downhill grades; streetcar or train tracks; and construction.Conclusions. The results of this study indicate that the design approach used in northern Europe is effective in North America. The following route types are the best choices for common urban transportation locations and would lower injury risks to cyclists: alongside arterials and collectors – cycle tracks; on local streets – designated bikeways with traffic diversion; and off-street – bike paths.
  Authors: Winters, Meghan; Harris, M. Anne; Reynolds, Conor C.O.; Cripton, Peter A.; Chipman, Mary L.; Cusimano, Michael D.; Brubacher, J.; Friedman, Steve M.; Monro, Melody; Vernich, Lee
  Authors: Winters, Meghan; Harris, M. Anne; Reynolds, Conor C.O.; Cripton, Peter A.; Chipman, Mary L.; Cusimano, Michael D.; Brubacher, J.; Friedman, Steve M.; Monro, Melody; Vernich, Lee
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-2995
  Practice-Ready: Yes
• Bayesian Modeling Approach for Cyclist Injury Risk Analysis at Intersections and Corridors
  Abstract: This study proposes a two-equation Bayesian modeling approach to simultaneously study cyclist injury occurrence and bicycle activity at signalized intersections as joint outcomes. This approach deals with the potential presence of endogeneity and unobserved heterogeneitiesand is used to identify contributing factors associated with both cyclist injuries and volumes. Its applicability in the identification of corridors at high-risk is also illustrated. An extensive inventory of a large sample of signalized intersections on the island of Montreal is used as the application environment. This inventory contains not only disaggregate vehicular traffic volumes and bicycle flows but also geometric design, traffic controls and built environment characteristics in the vicinity of the intersections. Among other results, this study identifies the importance of both bicycle and motor-vehicle flows on cyclist injury occurrence and further emphasizes the importance of turning motor-vehicle movements. It was also found that the presence of bus stops and total crosswalk width have a positive effect on cyclist injury occurrence whereas the presence of a raised median has a negative effect. The results also reveal that bicycle activity through intersections increases as employment, number of metro stations, land use mix, area of commercial land use type, length of bicycle facilities increase as well as in the presence of schools measured between 50 and 800 metres from the intersection. Also, intersections with three approaches are expected to have fewer cyclists than intersections with four approaches. Using Bayesian analysis, expected injuries and injury rates are computed to rank corridors. We found that corridors with high bicycle volumes, located mainly in the central neighbourhoods of Montreal, have lower risk despite having a high number of cyclists riding along each day. Most importantly, since there are more cyclists, these corridors have a greater chance of ranking high therefore confirming the "safety in numbers" effect.
  Authors: Strauss, Jillian; Miranda-Moreno, Luis Fernando; Morency, Patrick
  Authors: Strauss, Jillian; Miranda-Moreno, Luis Fernando; Morency, Patrick
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-2796
  Practice-Ready: Yes
• Roadway Users Want the Same Things: Results from a Roadway Design Survey of Pedestrians, Drivers, Bicyclists, and Transit Users in the Bay Area
  Abstract: Pedestrians, drivers, bicyclists, and public transit users all desire similar roadway design features, according to findings from a recent intercept survey along a major urban corridor in the San Francisco Bay Area. This research was sponsored by the California DOT to understand traveler preferences for street design that could increase perceived traffic safety, walkability, and bikability along urban arterials, as well as encourage economic vitality through increased patronage of local businesses. In an open-ended question about street improvements to enhance perceived traffic safety, all respondent groups requested the same top five improvements. Bicycle lanes were ranked first by individuals arriving to the survey location as pedestrians, drivers, and bicyclists (fifth by public transit respondents), and improved pedestrian crossings were ranked second by pedestrians, drivers, and public transit users (third by bicyclists). The other top five suggestions were the same for all groups, though ordered slightly differently: slowing traffic/improving driver behavior, increasing street lighting, and installing more traffic lights/stop signs. Similar preference alignment was found in response to an open-ended question about street improvements to encourage more visits to the corridor. These findings suggest that design features generally thought to benefit one road user group, such as bicycle lanes for bicyclists, may also benefit other user groups. Moreover, these results provide evidence that roadway planning can take advantage of synergistic opportunities to benefit multiple user groups by implementing a few key design interventions. Overall, the findings support the continued implementation of complete streets principles and policies.
  Authors: Sanders, Rebecca L.; Cooper, Jill F.
  Authors: Sanders, Rebecca L.; Cooper, Jill F.
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-4475
  Practice-Ready: Yes
• Bicyclist Safety Performance Functions for a U.S. City
  Abstract: Efforts have intensified to apply a more evidence-based approach to traffic safety. One such effort is the Highway Safety Manual, which provides typical safety performance functions (SPFs) for common road types. Unfortunately, the manual provides no SPFs for bicyclists, despite disproportionately high fatalities among this group. In this paper, a method for creating city-specific, bicycle SPFs is presented and applied to Boulder, Colorado, the first time a bicycle SPF has been created for a U.S. city. Such functions provide a basis for both future investigations into safety treatment efficacy and for prioritizing intersections to better allocate scarce funds for bicycle safety improvements. The SPFs demonstrate that intersections with more cyclists have fewer collisions per cyclist, illustrating that cyclists are safer in numbers.
  Authors: Nordback, Krista; Marshall, Wesley; Janson, Bruce N.
  Authors: Nordback, Krista; Marshall, Wesley; Janson, Bruce N.
  Year: 2013
  Document Type: Paper
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-5348
  Practice-Ready: Yes
• Cyclist Injury Severity in a Cycling Nation: Evidence from Denmark
  Authors: Prato, Carlo
  Authors: Prato, Carlo
  Year: 2013
  Document Type: Presentation
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-1547
• Bayesian Modeling Approach for Cyclist Injury Risk Analysis at Intersections and Corridors
  Authors: Strauss, Jillian
  Authors: Strauss, Jillian
  Year: 2013
  Document Type: Presentation
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-2796
• Bicyclists' Injuries and the Cycling Environment: Impact of Route Infrastructure
  Authors: Winters, Meghan
  Authors: Winters, Meghan
  Year: 2013
  Document Type: Presentation
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-2995
• Bicyclist Safety Performance Functions for a U.S. City
  Authors: Nordback, Krista
  Authors: Nordback, Krista
  Year: 2013
  Document Type: Presentation
  Subject: Pedestrians and Bicyclists; Safety and Human Factors
  Session: 454
  Paper Number: 13-5348