Bicycle helmet laws require bicyclists to wear helmets. Such laws may be established locally or statewide, and may apply to children or to all bicyclists. Penalties for violators vary, but are generally minor (Markowitz 2015*). Many bicyclists do not wear helmets; in a 2012 national survey of bicyclists, 46% of respondents over the age of 15 reported never wearing a helmet (NHTSA-Schroeder 2013).
Expected Beneficial Outcomes (Rated)
Increased helmet use
Reduced head injury
Other Potential Beneficial Outcomes
Reduced child deaths
Evidence of Effectiveness
There is strong evidence that bicycle helmet laws that require children to wear helmets increase helmet use (Cochrane-Macpherson 2010*, Karkhaneh 2006, Kraemer 2016a*, Carpenter 2011*, Jewett 2016) and reduce head injury among children (Cochrane-Macpherson 2010*, Walter 2011*, Markowitz 2015*, Olivier 2013*, Kett 2016*, Karkhaneh 2013*). Wearing a helmet can reduce fatal and non-fatal head and face injuries for bicyclists (Olivier 2017*).
Laws that require children to wear helmets appear to reduce bicycling-related deaths among children (Carpenter 2011*, Cochrane-Macpherson 2010*, Meehan 2013). Helmet laws that apply to all bicyclists may increase helmet use (Huybers 2017*) and reduce head injuries among children and adults (Kett 2016*, Olivier 2013*, Walter 2011*). Increases in adults’ helmet use may also lead to increased helmet use among children (Wesson 2008*).
Overall, helmet laws appear to increase helmet use more in areas with a low baseline proportion of helmet use than areas with high baseline use (Karkhaneh 2006). A study of high school students in urban areas suggests that bicycle helmet laws may increase helmet use among all racial groups; however, increases appear to be greater among white students than black and Latino students (Kraemer 2016b). A Canada-based study suggests that child-focused helmet laws do not increase disparities in helmet wearing among children by income level (Karkhaneh 2011*).
Researchers suggest enforcement penalties increase effectiveness of bicycle helmet laws (Williams 2018*).
Impact on Disparities
Citations - Evidence
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Cochrane-Macpherson 2010* - Macpherson A, Spinks A. Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries. Cochrane Database of Systematic Reviews. 2008;(3):CD005401.
Karkhaneh 2006 - Karkhaneh M, Kalenga J, Hagel B, Rowe B. Effectiveness of bicycle helmet legislation to increase helmet use: A systematic review. Injury Prevention. 2006;12(2):76–82.
Kraemer 2016a* - Kraemer JD. Helmet laws. helmet use, and bicycle ridership. Journal of Adolescent Health. 2016;59(3):338-344.
Carpenter 2011* - Carpenter CS, Stehr M, Journal S, May N. Intended and unintended consequences of youth bicycle helmet laws. Journal of Law and Economics. 2011;54(2):305–24.
Jewett 2016 - Jewett A, Beck LF, Taylor C, Baldwin G. Bicycle helmet use among persons 5 years and older in the United States, 2012. Journal of Safety Research. 2016;59:1-7.
Walter 2011* - Walter SR, Olivier J, Churches T, Grzebieta R. The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia. Accident Analysis & Prevention. 2011;43(6):2064–71.
Markowitz 2015* - Markowitz S, Chatterji P. Effects of bicycle helmet laws on children’s injuries. Health Economics. 2015:24(1);26-40.
Olivier 2013* - Olivier J, Walter SR, Grzebieta RH. Long term bicycle related head injury trends for New South Wales, Australia following mandatory helmet legislation. Accident Analysis & Prevention. 2013;50:1128–34.
Kett 2016* - Kett P, Rivara F, Gomez A, Kirk AP, Yantsides C. The effect of an all-ages bicycle helmet law on bicycle-related trauma. Journal of Community Health. 2016;41(6):1160-1166.
Karkhaneh 2013* - Karkhaneh M, Rowe BH, Saunders LD, Voaklander DC, Hagel BE. Trends in head injuries associated with mandatory bicycle helmet legislation targeting children and adolescents. Accident Analysis & Prevention. 2013;59:206-212.
Olivier 2017* - Olivier J, Creighton P. Bicycle injuries and helmet use: a systematic review and meta-analysis. International Journal of Epidemiology. 2016;46(1):278-292.
Meehan 2013 - Meehan WP, Lee LK, Fischer CM, Mannix RC. Bicycle helmet laws are associated with a lower fatality rate from bicycle-motor vehicle collisions. The Journal of Pediatrics. 2013;163(3):726-729.
Huybers 2017* - Huybers S, Fenerty L, Kureshi N, et al. Long-term effects of education and legislation enforcement on all-age bicycle helmet use: A longitudinal study. Journal of Community Health. 2017;42(1):83-89.
Wesson 2008* - Wesson DE, Stephens DS, Lam K, et al. Trends in pediatric and adult bicycling deaths before and after passage of a bicycle helmet law. Pediatrics. 2008;122(3):605-610.
Dellinger 2010* - Dellinger AM, Kresnow M. Bicycle helmet use among children in the United States: The effects of legislation, personal and household factors. Journal of Safety Research. 2010;41(4):375–80.
Kraemer 2016b - Kraemer JD. Bicycle helmet laws and persistent racial and ethnic helmet use disparities among urban high school students: A repeated cross-sectional analysis. Injury Epidemiology. 2016;3(1):21.
Karkhaneh 2011* - Karkhaneh M, Rowe BH, Saunders LD, et al. Bicycle helmet use four years after the introduction of helmet legislation in Alberta, Canada. Accident Analysis & Prevention. 2011;43(3):788-796.
Williams 2018* - Williams C, Weston R, Feinglass J, Crandall M. Pediatric bicycle helmet legislation and crash-related traumatic brain injury in Illinois, 1999-2009. Journal of Surgical Research. 2018;222:231-237.
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