Not all protected bike lanes are the same: infrastructure and risk of cyclist collisions and falls leading to emergency department visits in three U.S. cities

Cicchino, Jessica B. / McCarthy, Melissa L. / Newgard, Craig D. / Wall, Stephen P. / DiMaggio, Charles J. / Kulie, Paige E. / Arnold, Brittany N. / Zuby, David S.
Insurance Institute for Highway Safety
July 2019

Objective: Protected bike lanes separated from the roadway by physical barriers are relatively new in the United States. This study examined the risk of collisions or falls leading to emergency department visits associated with bicycle facilities (e.g., protected bike lanes, conventional bike lanes demarcated by painted lines, sharrows) and other roadway characteristics in three U.S. cities.
Methods: We prospectively recruited 604 patients from emergency departments in Washington, DC; New York City; and Portland, Oregon during 2015–2017 who fell or crashed while cycling. We used a case-crossover design and conditional logistic regression to compare each fall or crash site with a randomly selected control location along the route leading to the incident. We validated the presence of site characteristics described by participants using Google Street View and city GIS inventories of bicycle facilities and other roadway features.
Results: Compared with cycling on lanes of major roads without bicycle facilities, the risk of crashing or falling was lower on conventional bike lanes (adjusted OR=0.53; 95% CI=0.33, 0.86) and local roads with (adjusted OR=0.31; 95% CI=0.13, 0.75) or without bicycle facilities or traffic calming (adjusted OR=0.39; 95% CI=0.23, 0.65). Risk on one-way protected bike lanes did not differ from that on major roads (adjusted OR=1.19; 95% CI=0.46, 3.10). Two-way protected bike lanes were associated with higher risk than major roads when they were at street level (adjusted OR=11.38; 95% CI=1.40, 92.57), but lower risk when raised from the roadway or on bridges (adjusted OR=0.10; 95% CI=0.01, 0.95). Risk also increased in the presence of streetcar or train tracks relative to their absence (adjusted OR=26.65; 95% CI=3.23, 220.17), on downhill relative to flat grades (adjusted OR=1.92; 95% CI=1.38, 2.66), and when temporary features like construction or parked cars blocked the cyclist’s path relative to when they did not (adjusted OR=2.23; 95% CI=1.46, 3.39).
Conclusions: Certain bicycle facilities are safer for cyclists than riding on major roads. Protected bike lanes vary in how well they shield riders from crashes and falls. Less frequent intersections with roads and driveways, more continuous separation, and less complexity for turning drivers crossing them appear to contribute to reduced risk in protected bike lanes. Planners should minimize conflict points when choosing where to place protected bike lanes and should implement countermeasures to increase visibility at these locations when they are unavoidable.