Phones, traffic linked

0 Comments | Deseret News (Salt Lake City), Jan 3, 2008 | by Lucinda Dillon Kinkead Deseret Morning News

"Hang up and drive."

"Nice cell phone. Hope it gives you a brain tumor."

"WWJD? He'd hang up the cell phone and try not to hit me."

As cell phone use has intensified, so has the sentiment of bumper sticker messages for multitasking drivers. Now a University of Utah study has confirmed what is obvious to most Utahns -- drivers on cell phones are clogging up traffic.

Motorists on cell phones drive slower on the freeway, pass sluggish vehicles less often and take longer to complete their trips, according to a University of Utah study released Wednesday.

"At the end of the day, the average person's commute is longer because of that person who is on the cell phone right in front of them," says University of Utah psychology professor Dave Strayer, leader of the research team.

"That SOB on the cell phone is slowing you down and making you late," said Strayer.

Compared with nondistracted motorists, drivers on cell phones drove an average of 2 mph slower and took 15 to 19 seconds longer to complete the 9.2 miles. That may not seem like much but is likely to be compounded if 10 percent of all drivers -- as research shows -- are talking on wireless phones at the same time, researchers said.

Results showed when drivers talked on a cell phone, they made fewer lane changes, had a lower overall mean speed and a significant increase in travel time in the medium and high density driving conditions, researchers wrote in the study.

In medium and high density traffic, drivers talking on cell phones were 20 percent less likely to change lanes than drivers not on cell phones.

That may seem minor, said Joel Cooper, a doctoral student in psychology, who later this month will present the study at a Transportation Research Board meeting in Washington, D.C. The board is part of the National Academy of Sciences, National Academy of Engineering and Institute of Medicine.

"But if you have a lot of people who are not changing lanes and driving slower, this could substantially reduce traffic flow," Cooper said.

It's worse than that, said detective Jeff Bedard of the Salt Lake Police Department.

"Talking on the cell phone ranks up there with driving tired or driving while impaired," he said. "It may be that nine out of 10 times nothing happens, but on that one occasion where your attention is diverted is where you cause or are involved in an accident."

An insurance company survey estimated 73 percent of wireless users talk while driving. Another survey found that during any given daytime moment, 10 percent of drivers nationally are using cell phones.

Findings of the new study bolster already sturdy evidence that drivers should adhere to the bumper sticker admonishment: "Hang up and drive!" Other published research shows:

* Highway statistics suggest drivers on cell phones are four times more likely to be in an accident. Strayer's earlier research suggests the risk is 5.36 times greater.

* Hands-free cell phones are no less dangerous while driving than hand-held cell phones because the conversation itself is the major distraction.

* When young adults talk on cell phones while driving, their reaction times become as slow as reaction times for senior citizens.

* Drivers talking on cell phones are as impaired as drivers with the 0.08 percent blood alcohol level that defines drunken driving in most states.

* Cell phone users follow at greater distances, are slower to hit the brakes and are slower to regain speed after braking.

So old and new research combined means more traffic congestion, says Strayer.

"You have motorists on cell phones who tend to drive slower, their reaction times are slower, if they do hit the brakes it takes them longer to come back up to highway speed, and they are less likely to change lanes. Overall, they are more likely to gum up the highways."

Strayer says the study impacts any discussion of cell phone regulation. "They often don't factor in the cost to society associated with increased commute times, excess fuel used by stop- and-go traffic and increased air pollution, as well as hazards associated with drivers distracted by cell phone conversations," he said.

Indeed, two components -- accidents and delays -- are considered when looking at "user costs" associated with road travel.

"A fatal accident could cost as much as $5 million when we take into account medical, property and loss-of-income costs," says Peter Martin, director of the University of Utah Traffic Lab.

Delay is measured using a composite number representing the value of a typical American traveler's time -- about $13 per hour, according to Martin.

"If we compile the millions of drivers distracted by cell phones and their small delays, and convert them to dollars, the costs are likely to be dramatic," Martin said. "Cell phones cost us dearly."

E-mail: lucy@desnews.com