No clear evidence from countries that have enforced the wearing of helmets
This study examines the efficacy of helmet legislation in jurisdictions where helmet usage increased by at least 40%. To avoid confusing reductions in injuries (from safer roads or less cycling) with benefits of helmets, the author focused on percentages of cyclists with head injuries (the dataset included over 10,000 head injury cases).
The key findings of the study are:
- Case-control studies suggest cyclists who choose to wear helmets generally have fewer head injuries than non-wearers.
- Before and after data show enforced helmet laws discourage cycling but produce no obvious response in percentage of head injuries.
- This contradiction may be due to risk compensation, incorrect helmet wearing, reduced safety in numbers, or incorrect adjustment for confounders in case-control studies.
- Governments should focus on factors such as speeding, drink-driving, failure to obey road rules, poor road design, and cycling without lights at night.
In short, the study supports the position that helmets are great but helmet laws are not. Helmet laws discourage cycling and have no positive impact on cyclist safety. Studies that have claimed that helmet laws are a positive difference maker have failed to account for confounding variables such as other road safety measures.