Cars overtaking cyclists on different urban road types – Expectations about passing safety are not aligned with observed passing distances

Cycling has to be a safe activity, and perceived as such, if bicycle trips by all populations are to increase and the public health benefits are to be realized. A key characteristic of developed countries with a high cycling mode share is their provision of cycle tracks--separated bikeways along city streets--on major routes. This literature review therefore sought to examine studies of cycle tracks from different countries in order elucidate the safety of these facilities relative to cycling in the street and to point to areas where further research is needed. The review indicates that one-way cycle tracks are generally safer at intersections than two-way and that, when effective intersection treatments are employed, constructing cycle tracks on busy streets reduces collisions and injuries. The evidence also suggests that, when controlling for exposure and including all collision types, building one-way cycle tracks reduces injury severity even when such intersection treatments are not employed. However, the extent of this effect has not been well examined, as very few studies both look at severity and control for exposure. Future studies of the safety of cycle tracks and associated intersection treatments should focus foremost on examining injury severity, while controlling for exposure. In the U.S., where the obesity epidemic and its health consequences and costs are well documented, the benefits of increased cycling should be a focus of research and policy development in order to provide the infrastructure needed to attract people to cycling while minimizing injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.

A naturalistic experiment used an instrumented bicycle to gather proximity data from overtaking motorists. The relationship between rider position and overtaking proximity was the opposite to that generally believed, such that the further the rider was from the edge of the road, the closer vehicles passed. Additionally, wearing a bicycle helmet led to traffic getting significantly closer when overtaking. Professional drivers of large vehicles were particularly likely to leave narrow safety margins. Finally, when the (male) experimenter wore a long wig, so that he appeared female from behind, drivers left more space when passing. Overall, the results demonstrate that motorists exhibit behavioural sensitivity to aspects of a bicyclist's appearance during an encounter. In the light of previous research on drivers' attitudes to bicyclists, we suggest drivers approaching a bicyclist use physical appearance to judge the specific likelihood of the rider behaving predictably and alter their overtaking accordingly. However, the extent to which a bicyclist's moment-to-moment behaviour can be inferred from their appearance is questionable, and so the tendency for drivers to alter their passing proximity based on this appearance probably has implications for accident probability.