Is it true that trails and bike paths are more dangerous than roads?

There's an oft-quoted statistic that riding on a bike paths is 2.6 times more dangerous than riding on the road. The number comes from a 1974 masters thesis study of adult cyclists that was used by author John Forester in his book "Effective Cycling" to argue against separate bike facilities. The study compared reported crashes of adult cyclists (members of the League of American Wheelmen) on all types of roads and paths and found that bike paths were 2.6 times more dangerous per million bicycle miles traveled than major or minor highways.

However, things have come a long way since 1974. Sidewalks were designated for bicycle use and considered paths during that time -- and we now know that riding on the sidewalk, especially against the flow of traffic, greatly increases the chances of being involved in a crash with a motor vehicle. Other trails were narrow, windy paths that were poorly planned and designed -- and we now know that trails need to be a minimum of ten feet wide and should have ample sight distances, clear zones, and other features to make them safer. Worse still, many states had laws at that time requiring cyclists to use such designated paths even if they were less safe or convenient than the parallel roadway.

There is much more information available today on the appropriate selection of bicycle facility types. Trails or shared use paths are a tremendous asset when they are in their own right-of-way -- such as an old railroad corridor or stream valley -- and have very few intersections with crossing traffic. They are much less appropriate alongside major highways with numerous crossing streets, driveways, and other interruptions. The AASHTO Guide for the Development of Bicycle Facilities provides good information on the reasons why sidewalk bicycle paths don't work well and on the design details that help ensure bicyclists can safely use trails alongside pedestrians, joggers, and others.

So, a badly designed bike path on a sidewalk is indeed likely to be more dangerous than riding on the roadway. Equally, a rail-trail with grade-separated intersections, easy grades and a 12-foot paved surface is likely going to be a great alternative to a parallel busy arterial street with no safe space for bicyclists.