Bicycle Safety Guide and Countermeasure Selection System
Example of a wide outside lane. http://www.pedbikeimages.org/ - Libby Thomas
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. Wide curb lanes may be present on two-lane or multilane roads. A desirable width is 14 feet, not including the gutter pan area. Lanes wider than 14 feet sometimes result in the operation of two motor vehicles side by side. However, the WCL may need to be 15 feet wide on sections with steep grades or where drainage grates, wide gutter pans, raised reflectors, or on-street parking reduce the usable lane width. Wide curb lanes 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 and narrowing the other travel lanes on multilane roadways, especially when a section of roadway is resurfaced.
Wide curb lane 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. The 2012 AASHTO Guide for the Development of Bicycle Facilities discusses WCLs, but suggests that bike lanes or shoulders are the preferred facility type on major roadways when sufficient width is available. The Guide also discusses the use of signs and pavement markings on WCLs.
Wide curb lanes create on-street travel facilities for more experienced and confident bicyclists through marking lanes wide enough so that motor vehicles and bicycles have adequate room to share the lane during overtaking.
Normally, the only cost associated with WCLs is for re-striping the roadway. It is most cost efficient to create WCLs during street reconstruction, street resurfacing, or at the time of original construction.
Authors and Acknowledgements