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Effectiveness: 5 Star Cost: $$
Use: Medium
Time: Short

The purpose of bicycle helmet laws for children is to increase bicycle helmet use, thereby reducing the number of severe and fatal head injuries to children involved in bicycle crashes. Earlier crash-trend analyses using FARS data suggested that State helmet-use laws for children reduce child bicycle fatalities by about 15% in the long run (Grant & Rutner, 2004). Several meta-analyses discuss the effectiveness of bicycle helmets in reducing head injuries and fatalities in all types of crashes including bike-only falls (Attewell et al., 2001; Thompson et al., 2006). Elvik (2011) focused on all riders, not just children, estimating that bicycle helmet use results in about a 42% reduction in the risk of a non-fatal head injury. In another case control study, Bambach et al. (2013) found protective effects of helmet use to be 50% for moderate injury, 62% for serious injury, and 75% for severe head injury. Another study that examined emergency room visits of children who had bicycle-related injuries found that unhelmeted children were more likely to sustain injuries (40% versus 25.7%), meet the trauma activation criteria (45.5% versus 16.8%), and be admitted to the hospital (42.4% versus 14.9%). Overall, injury severity was worse with unhelmeted children, and these children were significantly more likely to have brain injuries, skull fractures, and facial fractures (Michael et al., 2017). Additional recent studies have reported increased risk of severe injury or death for non-use of helmets among riders involved in crashes. For more information, see the Bicycle Safety chapter, Section 2.1 Bicycle Helmet Laws for Adults.

A helmet law is a significant tool in increasing helmet use, but as with all laws, effectiveness is related to implementation. Legislation effectiveness is enhanced when combined with supportive publicity and education campaigns or programs. See, for example, Rivara et al. (1998), Kanny et al. (2001), Rodgers (2002), and Sandt et al. (2015). The practical effect of bicycle helmet laws is to encourage parents to require their children to use helmets (and educate parents to serve as role models to wear a helmet despite the lack of a law).

Law enforcement and other safety officials can reinforce the need to wear a helmet through positive interactions, free, or discounted helmet distribution programs (combined with proper helmet fitting), or other positive incentives for helmet use. Publicizing helmet laws and child/parent education on helmet fitting and the importance of wearing a helmet every ride may enhance effectiveness. Educational programs have been shown to increase knowledge about proper use of helmets. See the Bicycle Safety Chapter, Sections 1.3 and 3.2 for more information.

Use: As of March 30, 2019, there were 22 States, the District of Columbia, and at least 201 municipalities or counties that have child helmet laws (BHSI, 2019a). Most U.S. laws cover child bicyclists younger than 18. Only 13 States have no State or local bicycle helmet laws.

Effectiveness: Two systematic reviews found that legislation may be effective at increasing helmet use (Karkhaneh et al., 2006; Macpherson & Spinks, 2007). Two of three controlled studies reported reductions in head or traumatic brain injury following legislation (Macpherson & Spinks, 2007). The degree of improvement varied but there was a lack of evidence to determine whether enforcement, supporting publicity, and helmet distribution efforts explain some of the variation (Karkhaneh et al., 2006; Macpherson & Spinks, 2007). There was a non-significant trend toward a greater overall increase in helmet use in communities with laws covering all cyclists compared to those covering only children, and effects were larger among children (Karkhaneh et al., 2006). Dennis et al. (2010) also found self-reported helmet use was highest in a province with a law covering all ages, next highest in a province with a law covering children up to 18, and lowest in a province with no law.

A survey study of adults across the United States conducted by the CDC found that children who lived in States with child helmet legislation were more likely to wear a helmet (51% of respondents reported that their child always wears a helmet, and 21% self-reported their child never wears a helmet) than those in States that did not have a child helmet law (40% always and 35% never) (Jewett et al., 2016). In addition, the strongest predictor of child helmet use was adult helmet use. Parents who reported always wearing helmets were 40% more likely to report that their youngest child always wore a helmet than parents who did not always wear helmets. In Australia an observational study of helmet-law compliance was performed at 17 sites in Queensland, 24 years after mandatory helmet legislation was introduced in 1991 (Debnath et al., 2016). Video data of bicyclists (n = 27,057) showed overall high compliance rates, although children had a lower helmet wearing rate (94.2%) than adults (98.6%). Along roadways, children were more likely to be non-compliant than adults (5.1 times higher odds) and boys were less likely to be compliant than girls. Another study reported a clear and systematic increase in helmet use rates across Australian states following the introduction of bicycle helmet legislation (Olivier et al., 2019). The post-law rates increased from a range of 12% to 46% to a range of 71% to 85% for children (depending on the state), with the rates generally being lower than the rate increases for adult bicyclists.

Effectiveness of legislation in reducing head injuries is challenging to assess because of the difficulty of controlling for other safety measures that may differ across jurisdictions, and for exposure to crashes of different severities across people in case control studies. Two studies from Canada have found somewhat mixed results. Karkaneh et al. (2013) found that legislation targeting those less than 18 had a beneficial effect on child, adolescent, and adult bicyclists hospitalized for head injury in the province of Alberta, Canada. Helmet use increased from 75% to 92% among children, from 30% to 63% among adolescents, and from 52% to 55% among adults (Karkaneh et al., 2011). A national study compared trends in provinces with and without legislation. Despite lower injury rates in provinces with helmet laws than in those without, the effect could not be attributed to the introduction of the laws (Dennis et al., 2013). However, the study also found that one province that implemented a law covering all ages, not just children, did have a significantly lower injury rate trend for the period covered by the law.

Enactment of a helmet law can be effective even if the law is difficult to enforce. Bonander et al. (2014) found that the proportion of juvenile head injury hospitalizations in Sweden decreased by 7.8% for males younger than 14 after the enactment of a law requiring children to wear a helmet when riding a bicycle. Importantly, Swedish law prohibits law enforcement from issuing fines to children under 15, effectively preventing police from enforcing the law; however, the law may have been successful because it provided parents with additional leverage to persuade their children to wear a helmet.

Costs: A helmet law should be supported with appropriate communications and outreach to parents, children, schools, pediatric health care providers, and law enforcement. NHTSA has a wide range of material that can be used to educate and promote the use of a helmet every ride, demonstrate helmet effectiveness, and educate and demonstrate how to properly fit a helmet. Helmets that meet safety requirements can be purchased for under $20. Some States provide free or discounted helmets to some children (or parents if requested). When considering the costs of providing helmets, agencies should consider the benefits. A NHTSA summary of helmet laws reported that “every dollar spent on bicycle helmets saves society $30 in indirect medical and other costs” (NHTSA, 2008). The Bicycle Helmet Safety Institute has information on important considerations in buying a helmet, sources for low-cost helmets, and partners such as Safe Kids may be able to help with providing low-cost or free helmets ( A helmet should be replaced when it has been involved in a crash, when any part of the helmet is damaged, or the foam appears to be dry or changed in texture (brittle). According to BHSI, some manufacturers suggest replacement every 5 years, although BHSI indicates that it may depend on use and care of the helmet and that a helmet may provide good protection for longer (

Time to implement: A bicycle helmet law can be implemented as soon as the appropriate legislation is enacted. Enacting local ordinances may take less time than enacting statewide legislation. To develop custom communications and outreach, train LEOs on implementing the law, or start a helmet distribution or subsidy program in support of the law may require a medium-to longer-term effort.