People who talk on cellphones while driving, even using "hands-free" devices, are as impaired as drunk drivers, researchers said on Thursday.
"If legislators really want to address driver distraction, then they should consider outlawing cell phone use while driving," said Frank Drews, an assistant professor of psychology at the University of Utah who worked on the study.
The researchers used a driving simulation device for their study, published in the summer 2006 issue of Human Factors: The Journal of the Human Factors and Ergonomics Society.
They studied 40 volunteers who used a driving simulator four times -- while undistracted, using a handheld cell phone, using a hands-free cell phone and while intoxicated to a 0.08 per cent blood-alcohol level -- the average legal level of impairment in the United States -- after drinking vodka and orange juice.
Three study participants rear-ended the simulated car in front of them. All were talking on cellphones and none was drunk, the researchers said.
Motorists who talked on either handheld or hands-free cell phones drove slightly more slowly, were 9 per cent slower to hit the brakes, and varied their speed more than undistracted drivers.
Drivers with an 0.08 per cent blood-alcohol level drove a bit more slowly than both undistracted drivers and telephone users, yet more aggressively.
"Driving while talking on a cell phone is as bad as or maybe worse than driving drunk," said Drews, who said alcohol was involved in 40 per cent of the 42,000 annual US traffic fatalities.
Just like many people who have been drinking, the cellphone users did not believe themselves to be affected, the researchers found.