First, let’s clarify what safety paths are. The term safety path is apparently a local definition usually nearly exclusively within Oakland County, Michigan. AASHTO’s Guidelines for the Development of Bicycling Facilities contains the generally accepted standard terms and definitions for bicycle facilities. According to AASHTO’s definitions, safety paths are wide sidewalks.

Also from the AASHTO guidelines:

Utilizing or providing a sidewalk as a shared use path is unsatisfactory for a variety of reasons. Sidewalks are typically designed for pedestrian speed and maneuverability and are not safe for higher speed bicycle use. Conflicts are common between pedestrians traveling at low speeds and bicyclists… At intersections, motorists are often not looking for bicyclists.

It is important to recognize that the development of extremely wide sidewalks does not necessary add to the safety of sidewalk bicycle travel. Wide sidewalks might encourage higher speed bicycle use and increase potential for conflicts with motor vehicles at intersections, as well as with pedestrians and fixed objects.

There are two major studies that compared bicycle safety on roads and sidewalks.

Survey of North American Bicycle Commuters

A 1997 study by William E. Moritz compiled a Relative Danger Index for various bicycle facility types. This index was based on surveying 2,374 cyclists that had ridden 4.4 million miles.

• 1.28 Major Streets without Bike Lanes
• 1.04 Minor Streets without Bike Lanes (shared roadway)
• 0.50 Streets with Bike Lanes
• 5.32 Sidewalks

According to Moritz, bicycling on the sidewalk was over 10 times more dangerous than bicycling on a road with a bike lane.

Risk Factors for Bicycle-Motor Vehicle Collisions at Intersections

A 1994 study by Wachtel and Lewiston examined many factors affecting bicycle safety. One factor was road position. They compared cyclists riding on sidewalks versus riding on a road (both with and without bike lanes.)

Bicyclists on a sidewalk or bicycle path incur greater risk than those on the roadway (on aver­age 1.8 times as great), most likely because of blind conflicts at intersections. Wrong-way sidewalk bicyclists are at even greater risk, and sidewalk bicycling appears to increase the inci­dence of wrong-way travel.

Thus the aim of a well-designed roadway system should be to integrate bicycles and motor vehicles according to the well-established and effective principles of traffic law and engineer­ing, not to separate them. This conclusion is in accord with the 1981 and 1991 AASHTO Guides and the California Highway Design Manual, and with our own experience as bicy­clists. The goal of integration can be promoted through the use of wide, smooth outside lanes that encourage bicyclists to travel on the road­way rather than on an adjacent sidewalk or path.

Sidewalk bicycling adjacent to busy streets with many intersections presents special dangers, and should not be encouraged through the construction or designation of bicycle paths parallel to the street.

Call them Wide Sidewalks

The term safety path should be abandoned in local practice and replaced with the AASHTO definition. Not only to be on similar terms with the rest of the country, but to be accurate. These are not safe for most cyclists.

Tags: AASHTO, bike lanes, Safety, safety paths, sidewalk

This entry was posted on Sunday, July 13th, 2008 at 8:06 pm and is filed under On-road bicycling, Safety. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.