The mandatory helmet law isn't a first-order issue for cycling; the evidence that repeal would boost cycling significantly isn't convincing. The main game is infrastructure

It’s more than two years since I discussed directly the controversial issue of Australia’s mandatory helmet law (Should repealing the helmet law be a priority?). It’s timely to look at it again because in that time it’s hardly ever been out of the news. More recently, the NSW government’s decision to reinforce the law with draconian penalties and the Senate inquiry earlier this year into Personal choice and community impacts (the so-called Leyonhjelm inquiry) have garnered it plenty of attention.

I’ve written 23 articles on various aspects of the law since my first effort on 17 May 2011. I’ve read most of the “foundation” research documents that are continually cited by those engaged in this debate (but, I suspect, are read by few). Here’s my take on the significant issues associated with the discussion:

Travel by bicycle is a lot more likely to lead to some form of personal injury than other modes (see Is cycling on roads getting safer?).

Bicycle helmets are effective in mitigating the risk of head injuries, especially serious ones (see Do bicycle helmets work?). However, the level of risk varies with who’s riding and the type of cycling.

The increase in riders that would result from repealing the law would be quite small (see Should repealing the helmet law be a priority?).

It follows that repealing the law would have only a small positive impact via the “safety in numbers effect” and via increased exercise.

The avoided injury benefits from the law exceed the health dis-benefits from deterred cycling, probably significantly.

The key disincentive to cycling in Australian cities is far and away safety, both real and subjective. The key solution is better infrastructure and tighter regulation of driving.

The first time I wrote on this topic I said “the social benefits of mandating helmets are probably out-weighed by the costs”. I no longer think that’s a valid argument; the evidence simply isn’t there that the law deters cycling on a significant scale. There are quite a few who are annoyed by the law to varying degrees, but very few who are actually deterred from riding by it (see Should repealing the helmet law be a priority?).

It’s true the law is one of the reasons bike share continues to fail in Melbourne and Brisbane (see Is it time to wave goodbye to Melbourne Bike Share?). Note though that even if usage of Melbourne Bike Share were to quadruple in response to an exemption from the law (unlikely, but bear with me), its share of all weekday cycling trips by Melbourne residents would still be less than one percent; bike share is small beer (see It’s still ailing, so what next for Melbourne Bike Share?).

The most plausible objection to the law is that it’s a constraint on personal autonomy. I suspect that’s the key objection for many and explains why the issue consumes so much oxygen and excites so much passion. And it’s true that while the net health benefits of the law are very likely positive, it doesn’t automatically follow that helmets must therefore be compulsory. Indeed, a related complaint is that helmets are mandatory for cycling but not similar activities.

There’re heaps of other behaviours where there’d be a net health benefit if they were more strictly regulated but we choose not to take action. In this case the benefit from avoided head injuries needs to be assessed against the reduction in personal choice. That benefit might well be negative in situations where the risk of head injury is relatively low e.g. bike share and slow riding on off-road paths.

But there’s a practical problem; repeal has got little political traction outside a group of committed cyclists and libertarians. So far as the wider public are concerned the law is plain common sense, like seat belts. One survey found 94% of adult Australians regard the law as a non-issue (see What are governments prepared to do to improve cycling?). Governments aren’t likely to see much political advantage in repealing the law, even on a limited basis e.g. for bikeshare.

While I sympathise with those who find the law intrusive and discriminatory, in the absence of convincing evidence that repeal would significantly boost cycling, my view is the debate is a distraction. In spite of the law, cycling for all purposes by residents now has a higher mode share within 10-15 km of Melbourne’s CBD than trams (see How important is cycling in Australian cities?).

The law’s been in place in Australia for 25 years. It’s now part of the general background to cycling; it’s not the potent symbol it is in other countries where it’s currently proposed (see Should the UK make bicycle helmets compulsory?). In terms of its impact on the level of cycling in Australia it’s a second order issue.

I prefer to see energy focused on the sorts of actions – like improving infrastructure – that really do have the potential to drive large growth in cycling. When better infrastructure and regulation of drivers means our cities start approaching the level of safety offered by some European cities, the justification for the law – and likely the wider public’s support for it – will be greatly diminished.