Bicycle Helmet Safety Institute

Journal Articles and Studies
on Bike Helmet Laws

Summary: Here are references to a few of the many medical and scientific journal articles on the web about helmet laws and their effects. Most of them let you see the abstract summary for free, but ask you to pay for the full article. In some cases the abstract is all you need. The first listing is a unique summary of everything available on intervention strategies. We also have a page of links to journal articles including those not directly related to helmet law effectiveness.

Note: many of the articles below are from the Journal of the American Medical Association. They change the URL's from time to time and we may have missed a new one. If the links do not work, this search for helmet articles on the JAMA site should find most of them.

• A Systematic Review of Bicycle Helmet Laws Enacted Worldwide is a 2018 study of helmet laws worldwide done at Australia's UNSW Sidney by Esmaeilikia, Grzebieta and Olivier. The link is the full text .pdf file. It concluded: "There are currently 28 countries in total that have a bicycle helmet law. When the data is broken down in terms of countries, states, and cities, there have been at least 273 bicycle helmet laws enacted all over the world. Nine countries have bicycle helmet laws that apply to all ages as well as half of Canadian provinces, some US cities, urban travel in Chile and Slovakia, and interurban travel in Israel and Spain. To date, seventeen jurisdictions have modified their laws and only two laws have been fully repealed (Mexico City and Bosnia and Herzegovina)." In the intervening years the Portland, Washington State, USA law was also repealed.
  
  
• This New Zealand Medical Journal article by Ranul Makam confirms law effectiveness: "All reported increased helmet use; baseline rates of 4%-59% increased to 37%-91% following legislation and the pooled odds ratio for helmet use was 4.60. The authors note the plausible confounding effects of the variable promotional activities used to support legislation. However, they refer to evidence that benefit of legislation is conferred even in the absence of rigorous enforcement."
  
  
• Exploring the Relationship Between Mandatory Helmet Use Regulations and Adult Cyclists' Behavior in California Using Hybrid Machine Learning Models. Mineta Transportation Institute Publications, 2021. Fatemeh Davoudi Kakhki and Maria Chierichetti, San Jose State University "The goal of this research is to identify sociodemographic characteristics and cycling behaviors that are associated with the use and non-use of bicycle helmets among adults, and to assess if the enforcement of a bicycle helmet law will result in a change in cycling rates. This research develops hybrid machine learning models to pinpoint the driving factors that explain adult cyclists' behavior regarding helmet use laws." And further "Cyclists' gender, education level, perception of helmet use benefits and cycling risks, frequency of helmet use, type of bicycle, and frequency of bicycle use regardless of the purpose of riding either for work/commute or recreation, affect the perception of cyclists for the implementation of a mandatory helmet law in California."
  
  
• To helmet or not to helmet: a global perspective on the bicycle compulsory protective helmet law Minerva Pediatrics 2021 June;73(3):263-71 DOI: 10.23736/S2724-5276.20.05884-3. Baruch KLIN, Yigal EFRATI, Ibrahim ABU-KISHK. Three Israeli physicians researched the state of compulsory helmet laws for children worldwide and conclude: "to helmet or not to helmet" should not be a question anymore. A universal consensus on their compulsory use has to be achieved in order to improve children's safety.
  
  
• A Study of the Effectiveness of Bicycle Safety Helmets Among Children in Skaraborg County, Sweden (1991) Ekman, R and Welander, G. - Karolinska Institute, Department of Social Medicine, Kronan Health Center and Skaraborg County Council, Department of Health Promotion, Sit Olafsgatan 46, S-52135 Fallioping, Sweden
  
  
• Helmet legislation effectiveness in three NY counties - Dr Douglas R. Puder et. al. of the Department of Pediatrics, Nyack Hospital, Nyack NY November, 1999, issue of the American Journal of Public Health.
  
  
• Bicycle helmet use by children. Evaluation of a community-wide helmet campaign. DiGuiseppi et al. JAMA. 1989;262(16):2256-2261. doi:10.1001/jama.1989.03430160078034
  
  
• Bicycle Injury Hospitalisations and Deaths in Western Australia - 1981-1995. An Australian Government publication showing that "There was a decrease in the proportion of head injuries from almost half in 1981-1983 to just over a third in 1993-1995..." Now only available from the National Library of Australia.
  
  
• Impact of mandatory helmet legislation on bicycle-related head injuries in children: a population-based study. Macpherson AK, To TM, Macarthur C, Chipman ML, Wright JG, Parkin PC. Pediatrics 2002; 110(5):e60. Examines the effect of helmet laws on the rate of head injuries in four Canadian provinces. The bicycle-related head injury rate declined significantly (45% reduction) in provinces where legislation had been adopted compared with provinces and territories that did not adopt legislation (27% reduction). (Copyright 2002 American Academy of Pediatrics--full article is free on the web if you can find it.)
  
  
• Influence of Socioeconomic Status on the Effectiveness of Bicycle Helmet Legislation for Children: A Prospective Observational Study Patricia C. Parkin, MD, Amina Khambalia, MSc, Leanne Kmet, MSc, Colin Macarthur, MBChB, PhD. PEDIATRICS Vol. 112 No. 3 September 2003, pp. e192-e196 ELECTRONIC ARTICLE Abstract says "This study showed that bicycle helmet use by children increased significantly after helmet legislation. In this urban area with socioeconomic diversity and in the context of prelegislation promotion and educational activities, the legislative effect was most powerful among children who resided in low-income areas."
  
  
• Trends in Pediatric and Adult Bicycling Deaths Before and After Passage of a Bicycle Helmet Law. David E. Wesson, Derek Stephens, Kelvin Lam, Daria Parsons, Laura Spence, and Patricia C. Parkin. Pediatrics, Sep 2008; 122: 605 - 610. Examines bicycle-related mortality rates in Ontario, Canada, from 1991 to 2002 among bicyclists 1 to 15 years of age and 16 years of age through adulthood and to determine the effect of legislation (introduced in October 1995 for bicyclists less than 18 years of age) on mortality rates. The authors found that "For bicyclists 1 to 15 years of age, the average number of deaths per year decreased 52%..." Concludes that "The bicycle-related mortality rate in children 1 to 15 years of age has decreased significantly, which may be attributable in part to helmet legislation. A similar reduction for bicyclists 16 years of age through adulthood was not identified. These findings support promotion of helmet use, enforcement of the existing law, and extension of the law to adult bicyclists." Full article is free on the web.
  
  
• The effects of provincial bicycle helmet legislation on helmet use and bicycle ridership in Canada by Jessica Dennis, Beth Potter, Tim Ramsay and Ryan Zarychanski. Journal of Injury Prevention, August 2010.
  Data shows that bicycle usage remained constant after helmet laws were adopted in two provinces, and that helmet use was increased more by all-ages laws than by laws applying only to children. Helmet use data came from surveys, not actual observation.
  
  
• Bicycle helmet use after the introduction of all ages helmet legislation in an urban community in Alberta, Canada. Karkhaneh et al. Canadian Journal of Public Health, Vol 102, No 2, April 25, 2011. Evaluated the effect of mandatory bicycle helmet legislation for all ages in St. Albert, Alberta, using actual field observations. Helmet use increased from 45% to 92% (PR = 2.03; 95% CI: 1.72-2.39) post-legislation. Controlling for other covariates, children were 53% (PR = 1.53; 95% CI: 1.34-1.74) and adolescents greater than 6 times (PR =6.57; 95% CI: 1.39-31.0) more likely to wear helmets; however, adults (PR = 1.26; 95% CI: 0.96-1.66) did not show a statistically significant change post-legislation. CONCLUSIONS: Helmet legislation in St. Albert was associated with a significant increase in helmet use among child and adolescent cyclists.
  
  
• Trends in head injuries associated with mandatory bicycle helmet legislation targeting children and adolescents is another study about the Alberta experience.
  
  
• Implementation of all-rider bicycle helmet laws in the US
  "This research examined how bicycle helmet laws for riders of all ages are being implemented in select jurisdictions across the U.S. "
  
  
• Mandatory Bicycle Helmet Laws in the United States: Origins, Context, and Controversies
  "This article examines the origins and context of mandatory bicycle helmet laws in the United States...Controversy over these laws, particularly over whether they should apply universally or only to children, raised public health ethics concerns that persist in contemporary debates over bicycle helmet policies."
  
  
• Bicycle Helmet Use Among Maryland Children: Effect of Legislation and Education. Timothy R. Coté, Jeffrey J. Sacks, Marcie-jo Kresnow, Deborah A. Lambert-Huber, Ellen R. Schmidt, Andrew L. Dannenberg, and Cynthia M. Lipsitz Pediatrics, Jun 1992; 89: 1216 - 1220. Prelaw and postlaw helmet use was observed in Howard County (with a pre-law police campaign) and two control counties: Montgomery (with a community education program) and Baltimore County (no helmet activities). Prelaw helmet use rates for children were 4% for Howard, 8% for Montgomery, and 19% for Baltimore. Postlaw rates were 47%, 19%, and 4%, respectively.
  
  
• Children's bicycle helmet use and injuries in Hillsborough County, Florida before and after helmet legislation K D Liller et al. Explored the changes in children's bicycle helmet use and motor vehicle bicycle related injuries in Hillsborough County, Florida before and after passage of the state bicycle helmet law. The results show a significant increase in bicycle helmet use among children, ages 5-13, in the post-law years compared with the pre-law years. Also, there has been a significant decline in the rates of bicycle related motor vehicle injuries among children in the post-law years compared with the pre-law years. Although there have been complementary educational and outreach activities in the county to support helmet use, it appears that the greatest increase in use occurred after the passage of the helmet law.
  
  
• The rationale for promotion of bicycle helmet legislation for children up to 18 years (Israel) an article reviewing the evidence showing the effectiveness of helmets and setting out reasons why Israel should adopt legislation requiring them.
  
  
• Head first: Bicycle-helmet use and our children's safety August 2007 Canadian family physician Medecin de famille canadien 53(7):1131-2, 1136-7, Keezer et al. This Canadian article reviews Canadian injury and helmet use stats, as well as the effect of mandatory helmet laws. The authors conclude that legislation is called for in the remaining provinces who do not have laws.
  
  
• Bicycle safety helmet legislation and bicycle-related non-fatal injuries in California by Brian Ho-Yin Lee, Joseph L. Schofer and Frank S. Koppelman. Accident Analysis & Prevention, Volume 37, Issue 1 , January 2005, Pages 93-102. Compared developments in injury rates in California after adoption of helmet legislation covering kids. Adult rates did not change, while traumatic brain injuries among child riders went down 18%. We have a lot of questions about the data and the assumptions of this study. Available online for $30.
  
  
• This Cochrane Collaboration study found that helmet legislation "appears to be effective in increasing helmet use and decreasing head injury rates in the populations for which it is implemented. However, there are very few high quality evaluative studies that measure these outcomes, and none that reported data on possible declines in bicycle use."
  
  
  
• Intended and Unintended Effects of Youth Bicycle Helmet Laws a paper prepared at the University of California - Irvine that concludes that passing a state-wide bicycle helmet law reduces cycling by those who are covered by the law by 4 to 5 per cent. You can evaluate their methodology.
  
  
• Awareness of the bicycle helmet law in North Carolina reports on a study using a written survey that found that the majority of those returning the survey said they were aware that North Carolina has a helmet law.
  
  
• Bicycle Helmet Use in British Columbia: Effects of the Helmet Use Law reports on an evaluation conducted in 2000 at the University of North Carolina of the effectiveness of the BC law.
  
  
• Trends in pediatric and adult bicycling deaths before and after passage of a bicycle helmet law. An article about Ontario death rates after a helmet law was passed. Appeared in PEDIATRICS Vol. 122 No. 3 September 2008, pp. 605-610 (doi:10.1542/peds.2007-1776) The article examines bicycle-related mortality rates in Ontario, Canada, before and after helmet legislation. "For bicyclists 1 to 15 years of age, the average number of deaths per year decreased 52%, the mortality rate per 100000 person-years decreased 55%, and the time series analysis demonstrated a significant reduction in deaths after legislation." But for bicyclists 16 and over, there was no significant change. "These findings support promotion of helmet use, enforcement of the existing law, and extension of the law to adult bicyclists."
  
  
• Bicycle Helmet Laws Are Associated with a Lower Fatality Rate from Bicycle-Motor Vehicle Collisions. This 2013 Journal of Pediatrics study found that "bicycle helmet safety laws are associated with a lower incidence of fatalities in child cyclists involved in bicycle-motor vehicle collisions."
  
  
• The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia Scott R. Walter, Jake Olivier, Tim Churches, Raphael Grzebieta. Accident Analysis & Prevention, July, 2011. Hospital data modeled the ratio of head to limb injuries and found that cyclist head injuries decreased more than limb injuries at time of legislation. This article reports contrary views, but the paper they were based on has been retracted by the publisher for errors. Jake Olivier wrote a further article about this situation.
  
  
• No strong evidence bicycle helmet legislation deters cycling.
  Jake Olivier, Soufiane Boufous and Raphael H Grzebieta. Med J Aust 2016; 205 (2): 54-55. This 2016 Australian study found: "..there are reports indicating a decline in cycling based on convenience sampling data following the introduction of helmet legislation in Australia. However, there is also evidence based on better quality data which shows no significant impact on cycling participation. When faced with conflicting evidence, it is important to consider differences in study design and data quality. When these parameters are taken into account, the best evidence suggests that [mandatory helmet law] has never been a major barrier to cycling in Australia. In addition, the focus on helmet legislation detracts from more important discussions around the uptake of cycling. These include concerns for personal safety, which can be addressed by the construction of dedicated cycling infrastructure, education of all road users, and supportive legislation to protect cyclists, such as minimum passing distances."
  
  
• The impact of bicycle helmet legislation on cycling fatalities in Australia: Olivier J, Boufous S, Grzebieta R. Int. J. Epidemiol. 2019; ePub(ePub): ePub. This 2019 study concludes: "RESULTS: Immediately following bicycle helmet legislation, the rate of bicycle fatalities per 1?000?000 population reduced by 46% relative to the pre-legislation trend [95% confidence interval (CI): 31, 58]. For the period 1990-2016, we estimate 1332 fewer cycling fatalities (95% CI: 1201, 1463) or an average of 49.4 per year (95% CI: 44.5, 54.2). Reductions were also observed for pedestrian fatalities; however, bicycle fatalities declined by 36% relative to pedestrian fatalities (95% CI: 12, 54).
  
  "CONCLUSIONS: In the absence of robust evidence showing a decline in cycling exposure following helmet legislation or other confounding factors, the reduction in Australian bicycle-related fatality appears to be primarily due to increased helmet use and not other factors."
  
  
• Two studies noted here have concluded that critiques of helmet laws in Australia and New Zealand are bogus.
  
  
• Our page of links to journal articles has more studies not directly related to helmet law effectiveness.
  
  
• Our page for researchers has more sources.