The Surprising Risks of Playing It Safe

ByABC News
February 21, 2007, 3:43 PM

Feb. 22, 2007 — -- Deaths! Injuries! People are hurt every day. This is unacceptable, isn't it? We should do something about it. And when people want something to be done, they usually say that "there ought to be a law."

And so we get more laws meant to make us safer. Because 700 Americans die in bike accidents every year -- that's two a day -- lots of places now have passed laws requiring every biker to wear a helmet. It seems only sensible, since head injuries are what kill people. Public service announcements tells us that "a properly fitted helmet cushions the blow, protecting the head and brain from injury."

So helmets should protect people like me. For years I've ridden my bike to work, and for years I rode without a helmet. It was probably very dangerous. "20/20's" offices are in New York City, which means I had to weave in and out of traffic, hoping I didn't get hit by a car. This year, I finally started wearing a helmet. I wasn't forced to, New York has no law requiring adults to wear them, but my friends talked me into it, and frankly, I was surprised to discover that today's helmets are better; they're actually comfortable.

But does my helmet make me safer? Maybe not, because safety measures often have unintended consequences.

Ian Walker is an avid cyclist and a human behavior researcher at the University of Bath in England. He set up a bike with an ultrasonic distance sensor and camera, and rode for miles with and without a helmet. His data showed that cars reacted differently when he had the helmet on.

"When I wore a helmet, there was a quite considerable tendency for drivers to get closer," Walker said.

What's the reasoning, I wondered? Is it because a driver thinks, "Oh, that rider has a helmet. If I hit him, he'll live?"

No," Walker said. "It's that they're saying, 'He knows what he's doing.' When they see a cyclist who has all the gear, they think it's a sign of someone who's experienced and skillful."