Talking on your car phone while you are driving can be a dangerous practice. A report in tomorrow's issue of The New England Journal of Medicine concludes that you may run about the same risk of having an accident as you would if you were legally drunk. The good news is that, after a collision, you can easily call the police.
Donald Redelmeier and Robert Tibshirani, physicians at the University of Toronto, studied the phone logs of 699 cellular phone-owning drivers who reported accidents to Toronto's North York Collision Reporting Center. They looked at each person's phone activity immediately before the accident and compared it to their patterns of phone use at the same time on previous days, when driving conditions were likely to have been similar.
Redelmeier and Tibshirani's analysis showed that car phone conversations quadrupled drivers' risk of having a collision, an increase similar to that of driving while legally drunk. The risk did not vary between different age groups or levels of experience with driving or cellular phone use. And phones that allow your hands to be free offered no safety advantages, indicating that attention, not dexterity, is the missing ingredient, they said.
Despite the high correlation between accidents and cell phone use, other researchers--and the Toronto scientists themselves--point out that the current study draws no causal link between the two. "Simply talking while driving may be the key factor," says Murray Mittleman, an epidemiologist at Beth Israel Deaconess Medical Center in Boston. For that reason, say Redelmeier and Tibshirani, regulations on car phone use would be premature and could reduce one of the benefits of having a cellular phone: Almost 40% of the drivers in the study used their car phones to call emergency services after their collision. "Nevertheless," concludes Mittleman, "I believe the cellular-telephone industry should include warnings with their products."