What is a cycle track?
Cycle tracks, also known as sidepaths, are separated bicycle facilities that run alongside a roadway. Unlike bike lanes, cycle tracks are typically separated from automobile traffic by a physical barrier, such as parked cars, bollards, a landscaped buffer, or a curb. Cycle tracks may be one-way running with traffic, one-way running against traffic, two-way on the same side of the road, or two-way on both sides of the road. Though much more prevalent in European countries, several US cities have recently incorporated cycle tracks as a component of their bicycle facilities. Cambridge, Massachusetts, New York City, Portland, Oregon, and Washington, DC, have all constructed cycle tracks, some permanently and some as pilot projects.
One benefit of cycle tracks is that many bicyclists feel more comfortable being separated from traffic. Consequently, there are some indications that the availability of cycle tracks may attract new riders who otherwise do not feel safe or comfortable riding directly with cars. Cycle tracks may also reduce cyclist collisions involving parked cars; they can prevent "doorings" by creating a 2-3 foot gap between parked cars and the bicycle travel lane.
However, despite riders' perception that cycle tracks provide increased safety, research indicates that cycle tracks may actually cause a rise in certain types of collisions. In particular, cycle tracks may increase bicyclist-vehicle and bicyclist-pedestrian crashes at intersections and junctions. Parked cars and other barriers used to separate cycle tracks from traffic may cause reduced visibility at intersections and may make drivers less aware of the presence of bicyclists. Additionally, cyclists may have a false sense of security when using cycle tracks that may also make them less attentive to their surroundings (1).
As research and evaluation of cycle tracks is limited, particularly in the US, we have yet to gain a full understanding of how cycle tracks affect injury and collision rates and types or what effect they have on bicycle traffic levels. A before and after evaluation of cycle tracks in Copenhagen shows that collisions between intersections decreased by 10 percent while collisions at intersections increased by 18 percent. Cyclist traffic volumes increased 18-20 percent with the construction of cycle tracks (1). With few other evaluation studies, it is difficult to draw conclusions from these results.
Experience from other countries indicates that the design and location of cycle tracks can greatly impact their safety. Cycle tracks may be appropriate along roads that have high vehicle speeds and high traffic volume, but few intersections, driveways, and other junctions (2). Additionally, cycle tracks require a relatively wide right of way. The specific design of cycle tracks will depend on their context. Design considerations include the width of the cycletrack; distance from the road; type of buffer between the road and the cycle track; signage; and intersection treatments (pavement markings, signals, and turning facilities) (3). There are some general best practices to consider when constructing cycle tracks that may reduce some of the safety concerns associated with separated bicycle facilities. Cycle tracks should be at least wide enough to allow cyclists to pass one another - usually about 6.5 or 7 feet - but may be wider in areas with high bicycle traffic volume and narrower at intersections to slow bicycle traffic (2). Since many collisions associated with cycle tracks occur at intersections, the careful design of intersections is important. Options that may help address safety concerns at intersections include advanced stop lines or bike boxes, colored bike lanes, and traffic signals designated for bicyclists (3).
For a bibliography and summary of cycle track research:
Franklin, J. [no date]. Cycle path safety: A summary of research. Available at http://www.cyclecraft.co.uk/digest/research.html
For evaluation studies in Helsinki and Copenhagen:
Pasanen, E. [no date]. The risks of cycling. Helsinki, Finland: Helsinki City Planning Department. Available at http://www.bikexprt.com/research/pasanen/helsinki.htm
(1) Jensen, S.U., Rosenkilde, C., and Jensen, N. [no date]. Road safety and perceived risk of cycle facilities in Copenhagen. Copenhagen, Denmark: Trafitec, Inc. [English-language report.] Available at http://www.trafitec.dk/pub/Road%20safety%20and%20percieved%20risk%20of%20cycle%20tracks%20and%20lanes%20in%20Copenhagen.pdf
For more information on cycle track safety factors:
(2) Landis, B., Petritsch, T., Huang, H., McLeod, P., Challa, S. (2005) Sidepath facility selection and design. Tallahassee: Florida Department of Transportation. 29 p. Available at http://www.dot.state.fl.us/safety/ped_bike/brochures/pdf/Sidepath%20facility%20selection%20&%20design.pdf
Petritsch,T.A., Landis, B.W., Huang, H.F., and Challa, S. (2006). Sidepath safety model - Bicycle sidepath design factors affecting crash rates. Transportation Research Record, 1982, 194-201.
For more information on cycletrack design:
(3) Burchfield, R. [no date]. Cycle track lessons learned. Alta Planning and Design. Available at http://www.portlandonline.com/Transportation/index.cfm?a=228196&c=34816
