The Problem: Motorcycle crashes are a significant public health concern. In 2010, 4,502 drivers died in motorcycle crashes, and deaths related to such crashes increased 55% between 2000 and 2010, according to the CDC. The same report notes that the economic burden of motorcycle crashes was $12 billion in 2005. The public bears most of these costs through lost tax revenue, increased insurance premiums, and Medicaid spending. Multiple studies have shown that the injury and death rate among non-helmeted drivers is much higher than among helmeted drivers (See Liu BC, Ivers R, Norton R et al. Helmets for preventing injury in motorcycle riders. Cochrane Database Syst Rev 2008:1.)
The Law: Washington, DC and 19 states have universal helmet laws, which mandate helmet use for riders and passengers, e.g., Cal Veh Code § 27802. Twenty-eight states have partial helmet laws, which allow riders and passengers not to wear helmets if they are older than a certain age (ranging from 17 to 20) and possess insurance coverage over a specific dollar amount, see for example Fla. Stat. § 316.211 (3); MCLS § 257.658. Illinois, Iowa, and New Hampshire have no helmet laws. CDC: Motorcycle Helmet Laws By State.
The Evidence: A Community Guide review found that states with universal helmet laws experienced substantial increases in helmet use and decreases in fatal and non-fatal injuries compared to states with partial or no laws. The study also found that states that repealed universal helmet laws and replaced them with partial or no laws experienced sharp decreases in helmet use and increases in fatal and non-fatal injuries, see Guide to Community Preventive Services: Motorcycle Helmet Laws. The reviewers identified 69 studies with 78 study arms. Sixty-seven of the study arms evaluated motorcycle helmet use within the United States. The remaining study arms examined Australia, Italy, New Zealand, Spain, and Taiwan. The selected studies measured helmet use, non-fatal injuries (both total and head-related), total fatalities, and head-injury-related fatalities, as well as fatalities per individual crash, registered motorcycle, and vehicle miles traveled. The review included multiple study designs: ten study arms were interrupted time series, 14 were panels, 13 were time series or before-after with concurrent comparison groups, 39 were before-after, and 2 were cross-sectional. The reviewers observed that regardless of the study design and potential source of bias, universal helmet laws were consistently effective in increasing helmet use and decreasing both fatal and non-fatal injuries. The reviewers also found that partial laws are more difficult to enforce than universal laws, and are ineffective in motivating motorcyclists to wear helmets. An economic review, based on 22 studies, found that benefits to universal helmet laws heavily outweighed the costs.
The Bottom Line: According to a Community Guide systematic review, there is substantial evidence to support the effectiveness of universal helmet laws in increasing helmet use among motorcyclists, and to support that universal helmet laws reduce deaths, injuries and economic costs attributable to motorcycle crashes. Partial laws do not achieve any reduction in deaths, injuries or costs.