WASHINGTON - More people than ever are turning their cars into personal phone booths, with a million and a half drivers gabbing on cell phones at any given time. Women and young people are the most common yakkers.
About 10 percent of the people on the road during the day are using cell phones, up from 8 percent in 2004, the government reported Thursday.
Six percent of drivers were holding the phones to their ears, up from 5 percent last year.
The National Highway Traffic Safety Administration, which issued the report, recommends that motorists use cell phones while driving only during an emergency.
Connecticut, New York, New Jersey and the District of Columbia prohibit talking on hand-held cell phones while driving. The new data could add fuel to the debate over whether drivers should be limited in their use of cell phones on the nation's highways.
Cities such as Chicago and Santa Fe, N.M., require handsfree devices in automobiles. But eight states - Florida, Kentucky, Louisiana, Mississippi, Nevada, New York, Oklahoma and Oregon - bar local governments from restricting cell phone use in vehicles, according to the National Conference of State Legislatures.
Researchers have tried to figure out the possible risks of driving and dialing. A study published by the British Medical Journal in July found drivers using cell phones were four times as likely to get into a crash that could cause injuries serious enough to land them in the hospital.
But the study, conducted by the Virginia-based Insurance Institute for Highway Safety, suggested that using a handsfree device instead of a hand-held phone may not necessarily improve safety. Researchers found that both phone types increased the risk.
Industry officials contend cell phones are just one form of distraction: many drivers eat fast food, push buttons on their stereo, apply makeup or talk to other passengers.
"Talking on a cell phone is one of many possible distractions and by narrowly focusing on just this one could create a false sense of security with drivers," said John Walls, spokesman for CTIA - The Wireless Association.
Matt Sundeen of the National Conference of State Legislatures said state lawmakers have lacked the kind of conclusive data that was used in the past to bolster arguments for tougher drunken driving or seat belt laws.
"You don't have that wide body of accepted evidence yet on the driver distraction debate," Sundeen said.
The NHTSA survey was conducted between June 6 and June 25 at 1,200 road sites across the nation. Trained observers watched vehicles go by and charted what the driver was doing. The ages of drivers are estimates based on their observations.
The survey found that 10 percent of drivers between 16 and 24 were holding cell phones to their ears, compared with 8 percent in 2004. Only 1 percent of drivers ages 70 and above were using handheld cell phones.
Many states have sought restrictions for young drivers using cell phones. Ten states and the District of Columbia carry the prohibitions, with many of the laws approved in the past year.
The National Transportation Safety Board, meanwhile, voted in September to recommend that all states make it illegal for teenagers and new drivers to talk on the phone while driving.
Brian Schaffner, 24, who works for a political consulting firm in Washington, D.C., said his cell phone is "almost a part of me" and admits using it behind the wheel. But he doesn't think it affects his driving.
"I'm probably young and arrogant, thinking that I can't hurt myself, but for the most part I feel perfectly safe using when I drive," Schaffner said.
Women were more likely than men to use handheld phones behind the wheel, with 8 percent of women driving and talking into their cell phone, compared with 5 percent of men.
For the first time, the government examined drivers manipulating hand-held devices at the wheel, including dialing, typing a text message or playing a video game. Only 0.2 percent of drivers were observed fiddling with the gadgets.
Richard Roy, a state legislator in Connecticut who sponsored the state's ban on handheld devices, predicted the new data would help states pursuing similar laws.
"It will make it easier for other lawmakers to a get a law passed," Roy said.
On the Net:
National Highway Traffic Safety Administration: http://www.nhtsa.gov/
To see the NHTSA report: http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NCSA/RNotes/2005/809967.pdf