Wide Curb Lanes:

Wide curb lane in Ft. Lauderdale, FL.

Photo by Dan Burden

A wide curb lane (WCL) is the lane nearest the curb that is wider than a standard lane and provides extra space so that the lane may be shared by motor vehicles and bicycles. These facilities can also be placed on roads without curbs and are sometimes called wide outside lanes. WCLs may be present on two-lane or multi-lane roads. A desirable width is 4.3 m (14 ft), not including the gutter pan area. Lanes wider than 4.3 m (14 ft) sometimes result in the operation of two motor vehicles side by side. However, the WCL may need to be 4.6 m (15 ft) in width where drainage grates, raised reflectors, or on-street parking reduce the usable lane width. WCLs are sometimes designated when right-of-way constraints preclude the installation of "full width" bike lanes. WCLs are sometimes put in place by re-striping, especially when a section of roadway is resurfaced, by narrowing the other travel lanes.

WCL advocates believe that these wider lanes encourage bicyclists to operate more like motor vehicles and thus lead to more correct positioning at intersections, particularly for left-turning maneuvers. A previous FHWA publication recommends WCLs in many kinds of roadway situations where most bicyclists are experienced riders.4 Since WCLs are a shared-lane traffic situation, they are not signed or marked like a bike lane would be. As a result, many bicyclists do not know of their existence or utility as a bicycle facility. More detail on the comfort and safety of WCLs can be found in Hunter et al., 1999, and Harkey et al., 1996.3,5


  • Create on-street travel facilities for bicyclists.
  • Create a lane wide enough so that motor vehicles and bicycles have adequate room to share the lane during overtaking.

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  • Where WCLs are to be considered, the road or street should be evaluated to determine if this facility is appropriate.
  • Provide appropriate WCL width, especially where drainage grates or other factors reduce the usable lane width.
  • Consider the use of "Share the Lane" signing if used on a heavily traveled roadway.
  • Consider the use of a stencil such as the Shared Arrow or the SHARROW (developed in San Francisco) to help with proper bicyclist placement within the WCL and to encourage bicyclists to travel in same direction as motor vehicle traffic.
  • Truck traffic should not exceed five percent of the total motor vehicle traffic.

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Estimated Cost

Normally, the only cost associated with WCLs is for re-striping the roadway. A ballpark cost for large striping is $5,500 per km ($3,470 per mi). It is most cost efficient to create WCLs during street reconstruction, street resurfacing, or at the time of original construction.

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Case Studies

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