If you want to know what it's like to drive while drunk, skip the visit to your neighborhood bar and simply pick up a cellphone.
A growing body of scientific evidence suggests that people who speak or send text messages over mobile devices while driving behave a lot like people who are under the influence of alcohol, says David Teater, senior director of transportation for the National Safety Council (NSC).
Studies show that using a cellphone behind the wheel can dramatically impair driving, he adds. In simulation tests, the driving abilities of people using mobile devices are much like those of people whose blood alcohol content (BAC) level exceeds the legal limit for driving, which is .08 in the U.S.
Using cellphones while driving
"The solution is for people to stop using cellphones while driving," Teater says. "The NSC called for that in 2009. The National Traffic Safety Board called for that in 2011. [It’s] a significant safety threat."
A 2006 report from researchers at the University of Utah found that "the impairments associated with using a cellphone while driving can be as profound as those associated with driving while drunk."
In November, 2012 scientists from Australia and Spain reported the results of a study that compared the effects of alcohol consumption on drivers with the effects of using cellphones.
Participants included researchers from the University of Barcelona, Spain and four Australian institutions: Swinburne the University of Technology, the University of Wollongong, Victoria University and the Institute for Breathing and Sleep.
Two tests were conducted on separate days. In one, the participants consumed alcohol before simulated driving tests. Their driving abilities were monitored as their BAC levels gradually were raised to the .10 range, which is beyond the legal driving limit in most countries. The legal limit in the U.S. is .08
In the other test, the same participants had to simulate driving while using hands-free phones. Participants were asked to maintain their proper position in traffic lanes, maintain steady speeds, and apply the brakes when simulated obstacles appeared.
Researchers found that when hands-free phone conversations required the test subjects to answer complex questions, or when they were asked to respond to text messages, they performed as if their BAC was in the range of 0.07 to 0.10, according to a report on the study published by Academia.edu.
The study concluded that mentally challenging hands-free cellphone conversations, along with texting, represents a significant risk to drivers.
Paul Atchley, a professor of psychology at the University of Kansas, has been studying distracted driving for the past decade. He says the results of the study by researchers in Australia and Spain aren't surprising.
In some cases, intoxicated drivers actually can perform better than sober drivers who use cellphones, he adds. That's because the intoxicated drivers -- unlike most cellphone users -- know they are impaired. They compensate by driving more carefully.
Atchley says the human brain wasn't designed to multitask behind the wheel.
"We often fool ourselves into thinking that we can do more than we can do," he says. "We know from lots of studies if you are having a [cellphone] conservation with someone, that has an impact on the brain."
According to Carnegie Mellon University in Pittsburgh, activity in the parietal lobe -- the part of the brain that processes the movement of visual images -- decreases by as much as 37 percent when drivers listen to someone speak. Atchley says a driver's field of vision becomes narrower. That makes it difficult to remain aware of surrounding vehicles.
National Highway Traffic Safety Administration estimates 10 percent of all drivers are using a cellphone at any given moment, Teater says. "Nine percent of them are talking and 1 percent of them are texting."
Michael Barry, a spokesman for the Insurance Information Institute, says it's difficult to convince people just how dangerous it is to drive while talking on the phone or answering text messages.
"It is such a part of everyday life," he says. "I think that people just automatically reach for the phone for either a call or a text message."
James Whittle, assistant general counsel and chief claims counsel for the American Insurance Association trade group, says insurers worry about the problems cellphones pose.
"We are acutely concerned with distracted driving," he says. "Driving is one of the most hazardous things people do on a daily basis. People need to put down [mobile] devices and focus on the driving."