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The role of intersection and street design on severity of bicycle-motor vehicle crashes
  1. Morteza Asgarzadeh1,2,
  2. Santosh Verma2,
  3. Rania A Mekary3,
  4. Theodore K Courtney1,2,
  5. David C Christiani1
  1. 1Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
  2. 2Center for Injury Epidemiology, Liberty Mutual Research Institute for Safety, Hopkinton, Massachusetts, USA
  3. 3MCPHS University, Boston, Massachusetts, USA
  1. Correspondence to Dr Morteza Asgarzadeh, Harvard T.H. Chan School of Public Health/Liberty Mutual Research Institute for Safety, 401 Park Drive, Landmark, West Tower, 3rd Floor, Office #109, Boston, MA 02215, USA; Masgarza{at}


Background Safety concerns are a major barrier to cycling. Intersection and street design variables such as intersection angles and street width might contribute to the severity of crashes and the safety concerns. In this study we examined whether these design variables were associated with bicycle-motor vehicle crashes (BMVC) severity.

Methods Using the geographical information system and latitudes/longitudes recorded by the police using a global positioning device, we extracted intersection angles, street width, bicycle facilities, posted speed limits and annual average daily traffic from 3266 BMVC data from New York City police records. Additional variables about BMVC, including age and sex of the bicyclist, time of the day, road surface conditions, road character, vehicle type and injury severity, were obtained from police reports. Injury severity was classified as severe (incapacitating or killed) or non-severe (non-incapacitating, possible injury). The associations between injury severity and environment design variables were examined using multivariate log-binomial regression model.

Findings Compared with crashes at orthogonal intersections, crashes at non-orthogonal intersections had 1.37 times (95% CI 1.05 to 1.80) and non-intersection street segments had 1.31 times (95% CI 1.01 to 1.70) higher risk of a severe injury. Crashes that involved a truck or a bus were twice as likely to result in a severe injury outcome; street width was not significantly associated with injury severity.

Conclusion Crashes at non-orthogonal intersections and non-intersection segments are more likely to result in higher injury severity. The findings can be used to improve road design and develop effective safety interventions.

  • Outcome of Injury

Statistics from


  • Contributors MA developed the study idea, acquired and analysed the data and wrote the first draft. MA, SV and TKC provided statistical expertise and verified the accuracy of the used techniques. SV and TKC led the process of review and revision of the article. All authors contributed to results’ interpretation and manuscript's revision and approval.

  • Funding MA was supported by the Department of Nutrition at the Harvard T.H. Chan School of Public Health, Harvard University and the Liberty Mutual-Harvard Post-Doctoral Programme in Safety and Health.

  • Competing interests None declared.

  • Ethics approval The Harvard T.H. Chan School of Public Health Institutional Review Board (IRB) found that this study met the criteria for exemption and that additional review by IRB was not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement The authors obtained bicycle crash data from New York State Department of Annual-Average for the study. The data are publicly available.

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