How much safer do helmet laws really make us? Its a pretty simply question; the answer to which one would hope would form the basis of the government’s justification for the law in the first place. Yet in all the responses to ours and our reader’s letters, state governments have as yet been unable to answer this simple question.
The graph below shows the cumulative safety improvement of various transport modes in Australia over the period 1989-2010. The data comes from the Australian Fatal Road Crash Database and is normalised at 1991, the year helmet laws were introduced.
Without looking at the legend, see if you can tell which line represents cycling fatalities. Pretty tough isn’t it – click on the graph to see one with a legend.
The government claims that since the introduction of mandatory helmet laws, the number of cycling fatalities has decreased. And they are absolutely correct – they’ve gone from over 50 in 1991 to under 40 in the last few years. Yet this period has also been accompanied by a significant reduction in cycling numbers since the introduction of those laws.
How much of the fatality reduction has come from helmet efficacy and how much from fewer people cycling? Its hard to tell exactly because only very limited exposure data is kept for cycling in Australia (however the RTA, VicRoads and WA Transport all reported 30-40% reductions in cycling immediately after the introduction of helmet laws).
But while the data here doesn’t support any claim about cycling levels or safety-in-numbers, it does allow us to refute the claim that helmet laws make cycling safer.
To put it simply, if helmet laws had any impact on cyclist safety, then we would expect to see a reduction in head injuries and fatalities of cyclists, relative to other transport modes. Clearly, this is not the case. It may well be the case that some other factor occurred at the exact same time as helmet laws to make cycling more dangerous at the exact same amount that helmets made it safer, but without any evidence of this mystery factor, the official data from the Department of Infrastructure directly contradicts state government claims about helmet law efficacy.
What do you think? Is the government justified in mandating helmet laws when no evidence from the last 20 years supports the claim the helmet laws make cycling safer? Why don’t you tell you local MP what you think.