In my last article, Did the helmet law reduce commuting by cycling?, I identified a negative association between the level of cycling to work and the introduction of the helmet law in Australia in the early 1990s.
This time I’ve put together two exhibits which show the use of bicycles for the journey to work in Australia’s two most populous cities, Sydney and Melbourne, relative to the other “active” modes i.e. walking and public transport.
Both exhibits use Census data from a paper by Mees, Sorupia and Stone. I’ve omitted the biggest mode, driving to work, because it’s so large it makes varations in the smallest modes (like cycling) harder to see (1).
In both cities, the helmet law was introduced prior to the 1991 Census. It took effect 7 months before the Census in Sydney (NSW) and 13 months before in Melbourne (Victoria).
It seems evident that in terms of the contribution of cycling to the overall commuting travel task, the aggregate effect of the helmet law in these two cities was very small. Fluctuations in other modes had a considerably bigger effect on the overall pattern of travel.
I expect the law had a larger effect on the subset of male, blue collar workers who cycled to work in the suburbs of Sydney and Melbourne in the early 90s but, as I explained last time, the absolute number apparently deterred was extremely small.
This data only relates to the journey to work i.e. commuting. The law had a larger effect on teenage schoolboys of the early 1990s (e.g. see here, here and here) but cycling to school or for recreational purposes isn’t counted in the Census.
As I consistently point out, the journey to work only makes up around a fifth of all journeys. Nevertheless, it’s important because it’s the (non-recreational) trip purpose where cycling has shown the biggest gains in Australian cities.
It’s also important because work trips are longest, they’re the least discretionary and, because they’re subject to peaking, they determine the maximum capacity of transport infrastructure. They’re also the purpose where cycling is most likely to compete with – or complement – public transport (2).
So far as commuting in Sydney and Melbourne is concerned, the negative impact associated with the helmet law was extremely small. There are other arguments for reforming the law, but the historical record doesn’t suggest that significantly increasing the numbers of commuters who cycle is one of them.
Improving safety through measures such as better cycling infrastructure is an order of magnitude more likely to lead to a significant increase in the number of commuters riding to work.
Update: I’ve added charts for Brisbane, Perth and Adelaide. All charts are at the same scale.
- For clarity, I’ve omitted ferries from the Sydney chart because the curve lies on top of the cycling curve and makes it hard to see any perturbations in the latter. Also, I’m doubtful about the 1976 figures, but I’ve included them anyway to obviate wasteful debates with those who think they’re valid.
- Mees et al say: “there is no evidence from the census results that increases in cycling come at the expense of car driving. Rather, they seem to be mainly at the expense of walking and public transport.” Paul Mees elaborated on this theme in his book, Transport in Suburbia.