By Robbie Webber
Following in the footsteps of the NACTO Urban Bikeways Design Guide and an ongoing effort by AASHTO to develop standards for separate bike lanes, FHWA has also released a guide for designing and building these types of facilities. The guide includes elements that are not found in the other guides, such as recommendations for lane widths based on bicycle traffic volumes, guidance for where separated bike lanes (SBL) are appropriate based on motor vehicle speed and volume, and the horizontal separation of SBLs from motor vehicle lanes at intersections.
The guide also includes sections on how SBLs can coexist with transit stops, loading zones, accessible parking, and driveways. Recommendations for signage and signaling, lane markings, and planning for both motor vehicle and bicycle turning movements, and other technical best practices help planners and engineers solve questions that have kept SBLs from being more frequently implemented.
In preparation of the guide, the authors looked at design guides in North America (NACTO, Montreal, and British Columbia) and Europe (Denmark, Netherlands, and London) SBLs have been used in many European countries for much longer than in the U.S., and their design and usage guidance is more complete than what is available in North America. However, as these facilities have been installed in U.S. cities, best practices are emerging.
In Appendix A of the guide a literature review covers safety studies of existing SBLs and comparisons between similar roads with SBLs and those without bicycle facilities in North America. Both actual and perceived safety of users is covered, as well as the effect on ridership numbers when SBLs are installed. Previous research has established that traditional bike lanes significantly increase the comfort of bicyclists and increase ridership, however few studies have been done in North America since the installation of SBLs. This is an area the guide identifies as needing further research.
The authors of the guide and its previous supporting studies acknowledge that separated bike lanes are still a relatively new type of infrastructure in most of the U.S., and best practices are still emerging. But with planners, engineers, and the public eager to provide comfortable, safer bicycling facilities, the FHWA guide goes farther in providing guidance and official approval than anything to date.
Robbie Webber is a Senior Associate at SSTI.
By Robbie Webber