Bicycle Safety Guide and Countermeasure Selection System


Bike lane with on-street parking. - Dan Burden

Photo by Toole Design Group A bike lane painted green through the intersection makes the facility more visible and identifies potential conflict areas.
Photo by Toole Design Group


Flickr - Seattle Department of Transportation Markings can be used to create a buffer between the bike and motor vehicle lanes.
Flickr - Seattle Department of Transportation



Bike Lanes

Bike lanes indicate a preferential or exclusive space for bicycle travel along a street. Bike lanes are typically 4 to 6 ft wide and are designated by striping and symbols placed within the lane. Signage may also be used. Colored pavement or a contrasting paving material has also been used in certain situations to distinguish bike lanes from the motor vehicle lanes. Use of green colored bike lanes has interim approval from FHWA. Bike lanes are for one-way travel and are normally provided on both sides on two-way streets. Bike lanes may be placed against the curb where there is no parking and are usually designated to the left of parking or right turn lanes. Sometimes bike lanes are marked on the left side of a one-way street such as on streets where there are a high number of transit stops or vehicles on the right side, significantly more driveways, or where the majority of destinations are on the left side of the street.

Bike lanes have been found to provide more consistent separation between bicyclists and passing motorists than shared travel lanes. The presence of the bike lane stripe has also been shown from research to result in fewer erratic motor vehicle driver maneuvers, more predictable bicyclist riding behavior, and enhanced comfort levels for both motorists and bicyclists. Wider bike lanes (6 to 7 ft) and/or buffers provide additional operating space and lateral separation from moving and parked vehicles, thus increasing bicyclists sense of comfort and perceived safety (i.e., level of service) and reducing the risk of dooring from parked vehicles. Using buffers between the bike and motor vehicle lanes can also be used to visually narrow a wide street and create a more attractive and comfortable bicycling environment.


Bike lanes are used to create on-street, separated travel facilities for bicyclists. They can provide safety benefits to road users though separate operational space for safe motorist overtaking of bicyclists, particularly in narrow, congested areas. Bike lane presence also visually narrows the roadway or motor vehicle travel lanes to encourage lower motor vehicle speeds.


  • Where bike lanes are to be considered, the road or street should be evaluated to determine if this facility is appropriate.
  • Reallocating existing street space (narrowing other travel lanes, removing travel lanes, and/or reconfiguring parking lanes) is a way to create space for bike lanes.
  • Provide adequate bike lane width. Bike lanes should be a minimum 5 ft wide or 4 ft when not adjacent to on-street parking. Wider bike lanes (6 to 7 ft) should be considered in locations with high volumes of bicyclists, heavy parking turnover, higher vehicle speeds, higher traffic volumes, or a higher percentage of heavy trucks or buses.
  • Provide a smoothly paved surface and keep the bike lane free of debris. Avoid placing paving joints within the bike lane.
  • Wider (6 in) striping may be used to more visibly demarcate the bike lane from motor vehicle travel lane.
  • Provide adequate space between the bike lane and parked cars so that open doors do not create a hazard for bicyclists. This can be done by providing a wider bike lane or a painted buffer between the bike lane and parked vehicles. In more urban areas where motorists are more accustomed to parallel parking and tend to park directly against the curb, wider parking lanes (9 ft) have been used by some cities to provide more of a buffer between opening car doors and bicyclists.
  • Avoid termination of bike lanes where bicyclists are left in a vulnerable situation.
  • Determine if signs or markings are necessary for situations such as a high-volume of bike left turns on a busy roadway, or where right-turning vehicles must cross the bike lane.
  • Bike lanes require periodic sweeping to clear debris and should be cleared of snow in the winter.

Estimated Cost

The costs for bikeways shown below are assumed to include all costs including bikeway preparation, if applicable. However, costs were also identified for specific actions related to preparing a site for a separated bikeway, including excavation, grading, curb/gutter removal, and clearing and grubbing (removing vegetation and roots). Though cost information was limited, the following individual costs were obtained (all costs are approximate): excavation ($55 per foot); grading ($2,000 per acre); curb/gutter removal ($5 per linear foot); and clearing and grubbing ($2,000 to $15,500 per acre, depending on the width of the road and whether it is done on one or both sides of the road).

Min. Low
Max. High
Cost Unit
# of Sources (Observations)
Bicycle Lane
Signed Bicycle Route
Signed Bicycle Route with Improvements

Safety Effects

A summary of studies that have looked at the safety effects of bicycle lanes can be found here. The safety effects of colored bike lanes can be found here.


To view references for this countermeasure group click here.

Case Studies

Portland, Oregon
Santa Barbara, California
Eugene, Oregon
Cambridge, Massachusetts
University Place, Washington
San Francisco, California
St. Petersburg, Florida
Columbia, Missouri
University Place, Washington