PHILADELPHIA – Drivers who talk on cell phones may be just as dangerous as those who drink.

That’s the sobering conclusion of a study published Thursday by University of Utah researchers who monitored 40 men and women on a driving simulator.

And drivers using hands-free phones were no better than those with the hand held variety, confirming previous studies.

The findings, published in the journal Human Factors, represent a direct blow at a popular pastime that is taken for granted by millions of multitasking drivers.

At any given moment during the day, 10 percent of drivers on U.S. roads are gabbing away on their wireless devices, according to a 2005 estimate by the National Highway Traffic Safety Administration.

Bad idea, said psychologist Frank A. Drews, one of the Utah study’s authors.

“It’s kind of almost unpredictable how they are driving,” Drews said.

When using cell phones, drivers had slower reaction times and more accidents, and they drove inconsistently, sometimes approaching other cars then falling back, he said.

Cellular industry officials acknowledge that phones can be a distraction but said there are ways to use them sensibly. It is unfair to single out phones, said John Walls, a spokesman for CTIA – The Wireless Association, a Washington-based trade group.

“I think there are just a multitude of distractions that are out there,” Walls said. “And by focusing on just one, you’re creating a false sense of security among people.”

In another recent study by the Virginia Tech Transportation Institute, other distractions, such as applying makeup and reading, were found to be much more risky.

In the Utah study, both cell-phone use and alcohol caused participants to “drive” more erratically over the simulated 24-mile course, but in different ways.

Cell-phone users were involved in more “accidents” and they took about 70 milliseconds longer to react when the car on the video screen in front of them hit the brakes – a delay during which a car traveling 55 mph would cover more than 5 feet of road.

When the drivers were drunk – with a blood-alcohol content of .08 – they followed other cars more closely and they braked 23 percent more forcefully, a potential problem for motorists behind them. They also had twice as many close calls as they did when sober, defined as stopping less than 4 seconds away from a collision.

The participants were given a mixture of vodka and orange juice. Their level of drunkenness – equivalent to four drinks in an hour on an empty stomach for a 170-pound man – was verified with a breath monitor.

By one key measure, cell-phone users were even worse than drunk drivers.

When talking on the phone the drivers had three accidents, but when they were drunk they had none. The drivers also had no accidents when they were sober and not using phones.

Researchers said they were surprised that the drunk drivers were accident-free. They urged people not to misconstrue the results as suggesting that drunk driving is safe; there is no question it is not. The authors speculated that the lack of drunk accidents may have been due to the study’s being conducted during the morning, when participants were well rested.

Because the drunk drivers followed too closely and had more close calls, they would be expected to have accidents in the long run, Drews said.

The only states to ban driving while talking on a hand-held cell phone are Connecticut, New Jersey and New York. Washington D.C. and some other communities have done banned it too.

In New Jersey, police issued at least 7,000 tickets to drivers who were talking on cell phones during the first six months of 2005, the most recent time period available.

The real number of offenses is likely much higher, in part because charges are often negotiated away in municipal court, said Roberto Rodriguez, director of the state Division of Highway Traffic Safety. The law is also fairly new, having taken effect in July 2004, and enforcement may be inconsistent, he said.

Told of the new study, Rodriguez said he was not surprised that researchers found no difference between drivers who used hand-held phones and those who used the hands-free variety that is legal in New Jersey.

“You are not cognizant of what is going on around you” when having a phone conversation, the director said. “That is the danger.”

State Sen. Martha Bark, R-Burlington, a sponsor of the state’s handled cell-phone ban, said the exemption for the hands-free variety was a compromise in order to get an unpopular measure passed.

Bark said she got her own hands-free car phone only at her children’s urging, and that she uses it sparingly and pulls over when possible.

“I do not talk on my phone,” Bark said. “I call my office and say “I’m going to be 5 minutes late. Goodbye.”‘

Drews, the Utah researcher, said he never phones while driving. His reason is more than just the safety issue, he said.

“I believe that I don’t have to be accessible at any time,” Drews said. “I enjoy my quiet time.”

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