Recommended Bicycle Lane Widths for Various Roadway Characteristics

Abstract

Whether at the national, state, or local level, guidelines that have been developed for bicycle lane widths provide only general guidance on how bicycle lane widths should vary based on the conditions of the roadway. Thus, there was a need to conduct scientifically based research to develop more specific guidance on recommended bicycle lane widths for various roadway conditions. This report presents an analysis of the research and design guidance for bicycle lane widths on existing travel lane widths and parking lane widths. The research is based on a review of literature, the current state of practice, and a series of observational field studies. Temporary pavement markings were installed at several locations to delineate bicycle lanes of varying widths. The lateral positioning of both bicyclists and motorists was measured and used as surrogates to evaluate the safety effects of the allocation of roadway width between parking lanes, bike lanes, buffered spaces, and motor vehicle travel lanes. The data-collection sites included three midblock locations with on-street parking and two midblock locations where on-street parking was prohibited. The bicycle lane widths evaluated ranged from 3.5 to 6 ft. A supplemental grade study was also performed to evaluate lateral movement of bicyclists pedaling on a moderate upgrade. The report presents recommendations for bicycle lane widths for various roadway and traffic characteristics, including traffic volume, vehicle mix (i.e., percent trucks), lane width and/or total roadway width, and presence/absence of on-street parking. The conclusions are most applicable to urban and suburban roadways with level grade and a posted speed limit of 30 mph and should be used cautiously for the design of roadways with motor vehicle speeds outside of the range of 25 to 35 mph, and in particular for higher-speed roadways. This report will provide valuable guidance for traffic and design engineers in areas where bicycle lanes are being considered and implemented.