the BICE study
This study examined the association between bicyclists’ injuries and the cycling environment (e.g., route types, intersection types). The study took place in Toronto and Vancouver between May 2008 and November 2009. The participants were adults injured while bicycling and treated at hospital emergency departments. Five hospitals recruited participants, 690 in total.
The study’s “case-crossover design” is shown in the figure below. It allows the focus to be on infrastructure features. The comparisons are within a person-trip, thus controlling for personal characteristics and trip-specific weather and bicycle characteristics.
Of the 690 injured cyclists in the study, 59% were male. The injury trips were mainly on weekdays (77%), less than 5 km long (68%), and for utilitarian purposes (74%). Of the injury events, 72% were collisions (with motor vehicles, route features, people, or animals) and 28% were falls.
We found that route infrastructure does affect the risk of cycling injuries. The following features were the safest:
- cycle tracks (also known as “separated” or “protected” bike lanes) alongside major streets
- residential street bike routes with traffic diversion
- bike lanes on major streets where there were no parked cars
- off-street bike paths
- intersections with motor vehicle speeds below 30 km/h
- residential street intersections
The following infrastructure features had increased risk:
- streetcar or train tracks
- downhill grades
- sharrows (shared car / bike lanes)
- traffic circles at residential street intersections
- arriving at an intersection in the direction opposite to traffic
are safe routes preferred routes?
In our earlier study of route types that motivate and deter cycling, we found that people preferred to ride on bike-only paths, multi-use paths, residential street bike routes, and cycle tracks. They preferred NOT to ride on major streets.
The graph below compares our injury study results on route safety to the results on route preferences. Preferences and safety largely agree. Major streets are less safe and not preferred. Bike-specific routes are safer and preferred. The main disagreement was that multi-use paths are preferred, but were not particularly safe. They could be made safer by making them straighter so sight lines are better and by removing obstacles like bollards.
These results provide sound evidence for transportation planners, allowing them to select cycling infrastructure that will improve cycling safety. This should not only reduce the risk of traumatic injuries to cyclists, but, as a result, promote cycling as an urban transportation option, with attendant personal and public health benefits.
excellent route types to encourage cycling & prevent injuries
The photos below illustrate the safest infrastructure for each of three types of route:
presentations, posters, reports, files
Preliminary classification of the first 300 injury events was presented at the Canadian Association of Emergency Physicians conference in Montreal, June 2010.