title: Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case-crossover design.
abstract: BACKGROUND
  This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk.
  
  
  METHODS
  In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case-crossover design compared the infrastructure of injury and control sites within each injured bicyclist's route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801).
  
  
  RESULTS
  At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections.
  
  
  CONCLUSIONS
  These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure.
authors: School of Occupational and Public Health, Ryerson University, , Toronto, Ontario, Canada.
authors: M Anne
authors: MA
authors: Harris
authors: Conor C O
authors: CC
authors: Reynolds
authors: Meghan
authors: M
authors: Winters
authors: Peter A
authors: PA
authors: Cripton
authors: Hui
authors: H
authors: Shen
authors: Mary L
authors: ML
authors: Chipman
authors: Michael D
authors: MD
authors: Cusimano
authors: Shelina
authors: S
authors: Babul
authors: Jeffrey R
authors: JR
authors: Brubacher
authors: Steven M
authors: SM
authors: Friedman
authors: Garth
authors: G
authors: Hunte
authors: Melody
authors: M
authors: Monro
authors: Lee
authors: L
authors: Vernich
authors: Kay
authors: K
authors: Teschke
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data*; D000328:Adult; D001642:Bicycling / Q000293:injuries*; D001955:British Columbia; D016022:Case-Control Studies; D018592:Cross-Over Studies; D004779:Environment Design; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009864:Ontario; D017751:Safety Management / Q000379:methods*