Time to re-examine bicycle helmet laws?

Europe’s bike-sharing systems have inspired a number of North American cities — including New York and Montreal. In Paris, you can partake of something quite neat: Vélib, the most successful bike-sharing program in the world. You can buy a day pass online for $2, enter login information at one of the hundreds of docking stations that are scattered every few blocks around Paris and select one of Vélib’s nearly 20,000 bikes. But the most amazing thing you'll notice as you ride off is this - you'll ride off without a helmet. You'll ride all day feeling exhilarated, not fearful. You'll be surrounded by tons of bareheaded cyclists amid the Parisian traffic. One common denominator of successful bike programs around the world — from Paris to Barcelona to Guangzhou — is that almost no one wears a helmet and there is no pressure to do so.

In the United States the notion that bike helmets promote health and safety by preventing head injuries is taken as gospel. Un-helmeted cyclists are regarded as irresponsible, like people who smoke. Cities are aggressive in helmet promotion. But European health experts have taken a different view. Yes, some studies show that if you fall off a bike at a certain speed and hit your head, a helmet can reduce your risk of serious head injury. The thing is - such falls off bikes are rare — exceedingly so in mature urban cycling centres.

On the other hand, researchers say that if you pressure people to wear helmets, you'll discourage them from riding bicycles. The result is fewer ordinary cyclists on the road, which makes it harder to develop a safe bicycling network. The safest biking cities are places like Amsterdam and Copenhagen, where middle-aged commuters are mainstay riders and the fraction of adults with helmets is minuscule.

Pushing helmets kills cycling and bike-sharing in particular because it promotes a sense of danger that isn’t justified. Statistically, if we wear helmets for cycling, maybe we should wear helmets when we climb ladders or get into a bath, because there are more injuries during those activities. The European Cyclists’ Federation says that bicyclists (in Europe) have the same risk of serious injury as pedestrians per mile travelled.

Experience suggests that if a city wants bike-sharing to take off, it may have to allow and accept helmet-free riding. A two-year-old bike-sharing program in Melbourne, Australia — where helmet use in mandatory — has only about 150 rides a day, despite the fact that Melbourne is flat, with broad roads and a temperate climate. On the other hand, helmet-lax Dublin — cold, cobbled and hilly — has more than 5,000 daily rides in its young bike-sharing scheme. Mexico City recently repealed a mandatory helmet law to get a bike-sharing scheme off the ground.