Diet, Fitness, and Exercise: Does a helmet really help?
It seems logical that wearing a bike helmet makes a cyclist safer on the road. But Ian Walker, a traffic psychologist at the University of Bath in Great Britain and avid cyclist, began to question that logic when he and cycling friends noticed that cars seemed to give them less leeway when they were helmeted.
Walker tested his theory by having engineers rig up a bicycle that detected how much breathing room passing vehicles were giving him. He got on the bike and rodehalf the time helmeted, half bareheadedenough to be passed by 2,500 motorists. His results, which have been accepted for publication in the journal Accident Analysis & Prevention, confirmed his hunch: Drivers passed more than 3 inches closer when he was wearing a helmet. (Walker got hit twice during his experiment, once by a bus and once by a truck, and was wearing his helmet both times.) Being hit by a passing vehicle, he says, is a particularly dangerous kind of crash for a cyclist, who often falls beneath its wheels.
Walker theorizes that drivers perceive helmeted cyclists to be more skilledand therefore in need of less space on the road. One bus driver told him, "We know who the good ones are. They're the ones in the cycle lanes with helmets on." Walker also tested another theory by wearing a long wig while riding to give the impression that he was female; drivers gave him about 5 1/2 more inches of leeway than when he rode wigless.
Does this mean everyone should chuck their helmets and grow their hair? Not at all. The study points to a need for driver education, he says. And helmets are definitely good for low-speed falls that don't involve motor vehiclesthe kind of spills young kids are most likely to have.
But the study adds to the complex and contentious discussion about helmets, safety, and the law of unintended consequences. A review of the effects of mandatory helmet laws published earlier this year in the British Medical Journal questioned whether the overall effect on health was a good one. (Helmets are mandatory in New Zealand and parts of Canada and Australia, among other places; in the U.S., some state and local laws mandate helmet use for children under 18.) The author noted that because even nonhelmeted cyclists live longer than noncyclists, and regular exercise is good for overall health, "helmet laws would be counterproductive if they discouraged cycling and increased car use." Moreover, the author said, helmets might encourage cyclists to take more risks the same way that drivers wearing seatbelts may drive faster because they feel safer. Those who favor the laws say the bottom line is that bike-related head injuries declined among kids after the laws were passed.
Walker, for his part, is following up by studying drivers, using driving simulators to mimic the same experiment (with virtual cyclists, both helmeted and bareheaded), to find out whether the passing-distance differences break down by age or gender. He says a lot of accidents would easily be avoided if he got his fervent wish: "In an ideal world, it would be great to have drivers travel on bicycles for a month before they get their licenses."