Bike lanes separated from the roadway by physical barriers make cyclists feel safer and encourage more people to ride.
But a new IIHS study shows that protected bike lanes vary in terms of injury risk.
Factors such as the number of driveways or alleys intersecting the lanes and whether the lanes are one- or two-direction affect the likelihood of a crash or fall.
Compared with a major road with no bike infrastructure, the risk of a crash or fall was much lower on two-way protected bike lanes on bridges or raised from the roadway — for example, within greenways.
In contrast, the risk of a crash or fall on a two-way protected bike lane at street level was much higher than that of a major road.
One-way protected bike lanes differed little from major roads in terms of injury risk.
Among all types of cycling routes looked at in the paper, local roads had the lowest risk of a crash or fall.
Conventional bike lanes also had a lower risk in the study than major roads.
The risk was higher, however, at intersections.
It’s not clear why protected bike lanes would be more dangerous than conventional bike lanes, but it may have to do with the locations cities choose for protected lanes.