2.1 State Motorcycle Helmet Use Laws
Motorcycle helmets are highly effective in protecting motorcycle riders' heads in a crash. The latest research, using data from 1993-2002, showed that helmets reduce motorcycle rider fatalities by 37 percent (Deuterman, 2004; NCHRP, under review, Strategy F1) and brain injuries by 65 percent (NHTSA, 2003, p. 18; NCHRP, under review, Strategy F1). The Cochrane review, summarizing five well-conducted studies, estimated that helmets reduce head injuries by 72 percent (Liu et al., 2003). Helmets do not increase neck injuries (NCHRP, under review, Strategy F1; NHTSA, 2000a; Ulmer and Preusser, 2003, p. 8).
State helmet use laws are highly effective in assuring that almost all motorcycle riders wear helmets. Helmet use is well above 90 percent in States with a universal helmet law that covers all riders and about 34 percent to 54 percent in States with no law or a law covering only young riders (NHTSA, 2003, p. 18). Studies in States that enacted universal helmet laws observed use rates of 90 percent or higher after the law, compared to 50 percent or lower before the law (Ulmer and Preusser, 2003, Section II). States that repealed universal helmet laws saw the opposite effect, as use rates dropped from well above 90 percent to about 50 percent (Preusser et al., 2000, Section V; Ulmer and Preusser, 2003, Sections IV and V).
The first universal helmet law was enacted in 1966. Universal laws were in force in 47 States and the District of Columbia by 1975. After Federal penalties were eliminated in 1975 for States failing to have a universal law, about half the States repealed their laws. A few States have enacted or repealed helmet laws since then. Ulmer and Preusser (2003, Section II and Appendix) summarized the helmet law history in each State through 2001.
Use: As of July 2005, 20 States and the District of Columbia had a helmet law covering all riders. Most other States had a law covering only riders under a specified age, typically 18 or 21 (IIHS, 2004; NHTSA, 2005c).
Effectiveness: The General Accounting Office (GAO, now called the General Accountability Office) reviewed 46 methodologically sound studies of State helmet laws published before 1990. GAO concluded that motorcycle rider fatality rates were 20 to 40 percent lower with universal helmet laws (GAO, 1991, p. 4; Ulmer and Preusser, 2003, Section II). Studies since 1990 confirm these results (Ulmer and Preusser, 2003, Section II). GAO also noted that helmet use was low among young riders in States with laws covering only young riders. Laws covering only young riders are difficult to enforce because it is hard for law enforcement officers to estimate a motorcycle rider's age.
Costs: Once legislation requiring helmet use has been enacted, implementation costs are minimal. The inevitable controversy surrounding the legislation will publicize the new law extensively. Motorcycle helmet laws can be enforced during regular traffic patrol operations because helmet use is easily observed.
Time to implement: A universal helmet use law can be implemented as soon as the law is enacted.