December 02, 2008
Tuesday

If you're conversing behind the steering wheel, you'll drive more safely if your partner is sitting next to you rather than speaking from the other end of a cell phone.

That's because passengers will adjust a conversation in response to traffic conditions and will even break to remind the driver of hazards, according to new research by University of Utah psychologists.

"We find that it is actually good for a driver to talk to a passenger, one with driving experience. That is a person who will help you," said Frank Drews, an associate professor of psychology and lead author of the study released by the American Psychological Association.

Drews said that responsible friends don't talk on the phone to people who are driving. "If you are a responsible friend, you should be responsible and tell them you can talk later," he said.

The report, building on a growing body of research documenting the hazards of driving while using cell phones, will be published in the forthcoming edition of the Journal of Experimental Psychology: Applied. Drews recently produced an exhaustive review of the scientific literature on the influence of cell phones on driving and found little research on face-to-face conversations for points of comparison.

To fill this gap, the University of Utah researchers recruited 48 pairs of friends to talk to each other while one negotiated a virtual highway in a traffic simulator. In one round, the friends were together in the simulator, and in the other round, they spoke by phone. In both instances, the driver was asked to exit at a rest area.

Drews wanted to ensure that the conversation was engaging, so he had the friends talk about near-death experiences they had never shared with each other.

"Close calls are a really cool subject. They fascinate listeners very much," Drews said. "When they were talking by phone, half the drivers failed to leave the highway. They didn't see the exit sign to the rest area."

Researchers also documented driving ability that got worse during a cell conversation.

"You see bigger lane deviations for someone talking on a cell phone compared with a driver talking to a passenger," said co-author Dave Strayer, a Utah professor of psychology, in a news statement. "The passenger adds a second set of eyes, and helps the driver navigate and reminds them where to go."

To understand the "subtle mechanisms" behind these differences, the team examined how much the drivers and their partners spoke in terms of word production, and the complexity of their language. Their findings surprised them. Drivers talking on a phone used more words, but less complex sentences, as their driving situations became more demanding.

"It's crazy. They talk faster. It's quite counter-productive for driving safely," Drews said. "There is an obviously malevolent influence."

In previous studies, the psychologists found that use of a hands-free phone is just as distracting as hand-held devices. Drews was frustrated that some states' laws ban only the use of hand-held phones, giving the false impression that speaking on hand-free devices does not contribute to high-risk driving.

Such drivers are as likely to crash as an imbibing driver whose blood-alcohol content is at the legal limit of .08, the researchers say. But Drews cautioned against reading too much into this comparison because drunks drive more aggressively and their judgment is compromised. Phone-wielding drivers, by contrast, compensate for their impairment by driving more slowly and trailing other motorists at greater distances.

SitNews ©2008
Stories In The News
Ketchikan, Alaska

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