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The British Medical Journal ran a poll last week asking the question “Should it be compulsory for adult cyclists to wear helmets?“. Tellingly, the vast majority of those surveyed were against compulsion. While acknowledging the potential benefits of bike helmets if one was to receive an linear impact to the head, the justifications against compulsion highlighted the following key problems with helmet laws:
Bike helmet laws reduce cycling participation. Helmets are an inconvenience to some cyclists. While this probably doesn’t apply to sports or even fast commuter cyclists who already wear specific cycling attire and plan to shower on arrival, helmets are a significant inconvenience for cycling as a everyday form transport. And I don’t just mean helmet hair or the fashion factor (although helmet laws effectively rule out cycling as transport whenever hair style is an issue). Forcing people to wear a helmet makes cycling as transport inconvenient – just look at the failure of bike share programs in Australia.
Singling out cycling for mandatory helmet usage while not requiring it for similarly safe activities also sends a false message that cycling is dangerous. This ‘dangerising’ of cycling is a significant disincentive, especially to women, children and the elderly. This is another reason why cycling participation plummeted 30-40% after the introduction of mandatory helmet laws in Australia according to state transport authorities.
Bike helmet laws change cyclists and driver behaviour. Risk compensation and risk homeostasis explain how individual behaviour alters in the face of safety interventions. Whether it is that those put off cycling by helmet laws are more risk adverse or those who remain take more risks because the are now ‘safer’, helmet laws don’t seem to alter the ratio of head to non-head injuries or injury rates per unit of exposure. Yet cycling as transport, the form most discouraged by helmet laws, is even safer than the forms of cycling dominant in regions with helmet laws. Dublin’s bike share scheme had over 1.3 million journeys in its first year without a single serious incident. London’s scheme recently marked 4.5 million journeys 6 million and again, not a single serious injury. Finally, helmet wearing appears to affect motorist behaviour with drivers giving helmetless riders more passing room than those wearing helmets.
There is no evidence to support the claim that helmet laws increase cyclist safety. While there is plenty of science that explains how helmets can help if you suffer a head impact, there is not a single peer reviewed paper that demonstrates a link between helmet laws and improved cyclist safety. In Australia, cycling fatalities have decreased since the introduction of helmet laws, but less than the decrease for other non-helmet wearing road users. Proportions of fatalities caused by head injuries are the same for motorists, pedestrians and cyclists, while helmeted cyclists have the same incidence of head injuries as non helmeted cyclists. Whether it is ‘safety-in-numbers‘, the fact that helmet wearing provides little additional benefit in most motor vehicle collisions, or risk homeostasis, the fact remains that no study has been able to link helmet laws to improved safety.
Should bike helmets be compulsory for all cyclists? We don’t think so but please share your thoughts.
* The actual statistic was 68% of those BMJ subscribers polled were against mandatory bike helmet laws
It is far more difficult to persuade people with this logic once laws are in place, as here in Australia. Most people assume that the government based the law on good data and they are reluctant to believe the reality. That reality was that there was almost no cycle-specific data at the time of helmet mandation here and some of the “data” quoted was for motorcyclists, the rest was supposition.
In particular, the primary datum cited in the Victorian government’s Regulatory Impact Statement, that helmets prevent 80% of head injury, was pure guesswork from someone in North America.Twenty-one years later we do have somewhat better data.However data was not really the issue. It was the motoring organisations and the parent’s groups that pushed for the law and the government was in a very weak position prior to an election. It was desperate for votes in the marginal electorates of the outer-suburban swinging electorates.
An excellent précis, John. We agree.