PW 1341 A systematic review of the impact of bicycle helmet legislation on cycling exposure

Abstract

BackgroundCycling is a physical activity with many health and environmental benefits. There are inherent risks while cycling and bicycle helmets have been proposed as a means to mitigate head injury along with crash avoidance strategies such as separated cycling infrastructure. Twenty-seven countries around the world have enacted bicycle helmet legislation (BHL) to increase helmet usage among cyclists. Critics of BHL often claim legislation deters cycling uptake.MethodsFive electronic databases (MEDLINE, EMBASE, COMPENDEX, SCOPUS, WEB OF SCIENCE) were searched to identify relevant studies. Two authors independently assessed records retrieved in adherence to the PRISMA statement. The included studies reported data on cycling exposure pre- and post-legislation.Results22 studies with data from 6 countries covering 16 jurisdictions were identified from the peer-reviewed and grey literature. The methods used to measure cycling include direct observation at fixed locations, self-reported surveys, hospital data, police-reported crashes and movement counters. Most studies had a single pre-legislation observation making it impossible to estimate existing trends. Although BHL exists in 27 countries, our systematic review identified studies from Australia, Canada, New Zealand, Spain, Sweden and the United States.ConclusionsIn our preliminary results, most studies found no or conflicting evidence of reductions in cycling following BHL. In the few studies reporting reductions in cycling following BHL, these could be due to existing trends or a general shift from active transport modes to personal motor vehicle travel. Due to the lack of data across most jurisdictions with BHL, caution should be exercised when interpreting these results.

Cycling related major trauma in Ireland

“…More research is needed in this area to identify variables which are not included in the study that may contribute to the occurrence of head injuries. It is commonly thought that mandating helmet use may reduce the modal share of cycling and in turn decrease the 'safety in numbers' effect increasing overall collision risk for cyclists, though a recent meta-analysis indicated that this may not be the case [52][53][54]. The positive effect of mandating helmet use is expected to be greater for jurisdictions with low initial wearing rates, and the use of helmets already is actively encouraged by road safety stakeholders in Ireland leading to a high helmet wearing rate as indicated by this study.…”