Should wearing bicycle helmets be voluntary?

If fonts were dogs

I wouldn’t cycle in Melbourne without a helmet and I think anyone who chooses to cycle on the roads of our fair city without one is either an actuary or a statistics nerd. But as this raging debate shows, many people evidently would.

One reason I’m risk-averse about cycling is the experience of ‘dropping’ my bike with my son strapped in the child seat when he was two. While it was a low-speed accident, he banged his head on the road – fortunately it was encased in a helmet. Would he have been injured if he wasn’t wearing one? I don’t know for sure but I’m very glad I didn’t have to find out.

Another reason is I once worked with a woman whose teenage brother died many years before when he fell off his bike and hit his head on a gutter. This happened back in the days before anyone even thought to wear a helmet. Probably most importantly, I have a relative, a surgeon, who worked on a bicycle trauma study in Qld in the 80s and impressed on me the severity of head trauma suffered by cyclists, almost all of them children.

I wear a helmet because it’s a limited form of insurance against an unlikely but potentially catastrophic event. Like any insurance, the most likely outcome is I’ll pay more in ‘premiums’ than I’ll get back in ‘pay-outs’, but it’s protection against the remote possibility of absolute disaster. I know it won’t offer anything like the protection of a motor cycle helmet, but it will help in some sorts of low-impact events that might otherwise be deadly.

A helmet has no effect on my propensity to cycle. I’m a regular cyclist who commuted for many years, and I’ll always insist on wearing one. But making helmets mandatory for all cyclists is another matter altogether. While there’s still plenty of dispute, from the evidence I’ve seen, the social benefits of mandating helmets are probably out-weighed by the costs.

The key argument against compulsory helmets is they discourage people from enjoying the health benefits of cycling and from generating the associated environmental payoffs. It seems likely these foregone benefits exceed those from avoided head trauma. Also, discouraged riders diminish the number of cyclists on the road and thereby make cycling in traffic more dangerous for all riders.

The “discouraged cyclist” effect manifests in a number of ways. There’s unwanted ‘helmet hair’. Always having a helmet on hand can be inconvenient. Helmets are uncool in some demographics, particularly among children. In hot weather they can be very uncomfortable. Probably most importantly, making helmets compulsory helps create the idea that cycling is inherently more dangerous than it actually is.

The debate isn’t really about the value of choosing to wear a helmet, it’s about whether or not the net benefits at a social level warrant compelling everyone to wear one. I subscribe to the view that any restriction on personal behaviour needs to have pretty strong and unambiguous net benefits to be justified.

The circumstances at the time bicycle helmets were made mandatory (1991 in Victoria) were very different to today. The fatality rate from road accidents was far higher than it is now – there were 13.7 fatalities per 100,000 population in Australia in 1990, versus 6.8 in 2009. Probably most importantly, cycling was seen as something only children – vulnerable and immature – did on a serious scale. New research in the 80s on cycling-related head trauma, mostly among children, made compulsory helmets an easy and widely-applauded decision. At the time, the benefits doubtless seemed strong and unambiguous. Read the rest of this entry »