Citation

Jackson S, Retting RA, Miller S. U.S. National Highway Traffic Safety Administration. U.S. National Highway Traffic Safety Administration, 2021.

Copyright

(Copyright 2021, U.S. National Highway Traffic Safety Administration)

The full document is available online.

Abstract

Many States enacted bicycle traffic safety laws to improve safety for bicyclists. This study examined the effects of six laws (safe passing, mandatory helmet use, bicycling under the influence, where-to-ride, sidewalk riding, and the Idaho stop) on bicyclist safety metrics to determine if States and communities should create separate laws that govern bicyclists on roadways, and if bicyclist-specific traffic safety laws protect bicyclists from motor vehicle crash injuries and fatalities. Data on police-reported crashes involving bicyclists were collected from 34 States, with 28 coming from NHTSA's State Data System (SDS) over a number of years. Safety metrics of each law were modelled using generalized linear mixed models. States with safe passing (SP) or where-to-ride (WTR) laws experienced 23 percent and 13 percent fewer related crashes, respectively, relative to States with none. States with both SP and WTR laws had 12 percent fewer. Post-enactment, SP-only States had 11 percent more related crashes annually, while WTR-only States had 0.4 percent more, and States with both had 5 percent more. Helmet use was 20 percent higher in States with mandatory helmet use (MHU) laws and increased 7 percent each year after the laws were enacted. Fatalities and incapacitating injuries were found to decrease by 2 percent in States with MHU laws. States with bicycling-under-the-influence (BUI) laws had 38 percent fewer crashes of intoxicated bicyclists than States without such laws, and additional annual decreases of 8 percent post-enactment. Roadway crashes fell 4 percent in States with permissive sidewalk-riding (SR) laws compared to States with no SR law. States with permissive SR laws had 94 percent fewer intersection-related roadway crashes and 656 percent more intersection- related sidewalk crashes.