A report from the University of Utah says when motorists between 18 and 25 talk on cell phones, they drive like elderly people — moving and reacting more slowly and increasing their risk of accidents.
"If you put a 20-year-old driver behind the wheel with a cell phone, his reaction times are the same as a 70-year-old driver," said David Strayer, a University of Utah psychology professor and principal author of the study. "It's like instant aging."
And it doesn't matter whether the phone is hand-held or handsfree, he said. Any activity requiring a driver to "actively be part of a conversation" likely will impair driving abilities, Strayer said.
In fact, motorists who talk on cell phones are more impaired than drunken drivers with blood-alcohol levels exceeding 0.08, Strayer and colleague Frank Drews, an assistant professor of psychology, found during research conducted in 2003.
Their new study appears in this winter's issue of Human Factors, the quarterly journal of the Human Factors and Ergonomics Society.
Strayer said they found that when 18- to-25-year-olds were placed in a driving simulator and talked on a cellular phone, they reacted to brake lights from a car in front of them as slowly as 65- to 74-year-olds who were not using a cell phone.
In the simulator, each participant drove four 10-mile freeway trips lasting about 10 minutes each, talking on a cell phone with a research assistant during half the trip and driving without talking the other half. Only handsfree phones — considered safer — were used.
The study found that drivers who talked on cell phones were 18 percent slower in braking and took 17 percent longer to regain the speed they lost when they braked.
The numbers, which come down to milliseconds, might not seem like much, but it could be the difference to stopping in time to avoid hitting a child in the street, Strayer said.
The new research questions the effectiveness of cell phone usage laws in states such as New York and New Jersey, which only ban the use of hand-held cell phones while driving. It's not so much the handling of a phone, Strayer said, but the fact that having a conversation is a mental process that can drain concentration.
The only silver lining to the new research is that elderly drivers using a cell phone aren't any more of a hazard to themselves and others than young drivers. Previous research suggested older drivers may face what Strayer described as a "triple whammy."
"We thought they would be really messed up because not only are they slower overall due to age, there's also a difficulty dividing attention," Strayer said.
But the study found that more experience and a tendency to take fewer risks helped negate any additional danger.