Updated

Hand-held cell phone use while driving will be illegal in the nation's capital starting on July 1 and a ban is soon to be signed into law in New Jersey.

The Washington, D.C., city council last week followed New York state's 2001 lead and passed a ban on the increasingly common practice. On Monday, New Jersey's legislature gave final approval to a bill prohibiting drivers from using hand-held cell phones. Gov. James E. McGreevey is expected to sign it.

The new prohibition is part of the increasing attention being paid to the dangers of cell phone use while driving as well as other distractions such as putting on makeup, eating and changing CDs.

"Our research indicates pretty strongly that there is a whole array of distracted driving things. We believe that cell phones are just the proverbial tip of the distracted-driving iceberg," said Lon Anderson, director of public relations and governmental research for the American Automobile Association (search).

The National Highway Traffic Safety Administration (search) estimates that driver distraction is a contributing cause of 20 to 30 percent of all motor vehicle crashes, amounting to 1.2 million accidents a year.

According to the National Conference of State Legislatures (search), 140 million Americans use mobile phones. Among them, 50 to 73 percent admit to using their phones while driving.

In 2003, 42 states considered 116 bills related to cell phone use while driving or other distracted driving behaviors. Seventeen states have laws limiting cell phone use on the road.

Despite the rising awareness about this issue, some experts warn that the few studies completed on cell phone use and distracted driving have not conclusively exposed potential dangers.

Cell phone use "appears to pose some risk, but it's not clear what the magnitude of that risk is," said Joshua Cohen, senior research associate at the Harvard Center for Risk Analysis (search).

"The one state that has prohibited the use of cell phones is New York and they haven’t collected any data to see if the total number of accidents has dropped," said Matt Sundeen, who authored a report titled "Cell Phones and Highway Safety" for the NCSL.

As of November 2003, only seven states had conducted studies on the impact of cell phone use while driving, while several states have acknowledged the difficulty in tracking this data.

Quantifying the importance of cell phones in a crash is more difficult than measuring the impact of alcohol or the lack of seatbelts because authorities must rely on an eyewitness or self-reporting, Sundeen said.

The New York, New Jersey and D.C. laws allow hands-free cell phone use, a provision that concerns Cohen, who questions whether the distraction caused by talking is as great for drivers whether or not they are holding the phone.

"There is virtually no real world evidence or data that have been collected to quantify how big the incremental crash risk is that is associated with hand-held use," he said.

Jonathan Adkins, spokesman for the Governors Highway Safety Administration (search), a nonprofit association that represents the highway safety interests of states and territories, said he believes that hands-free phones are also dangerous, but questioned whether cell phone bans of any type are useful. Adkins suggested that such behavior perhaps be regulated by common sense, not the state police.

Drivers have been largely supportive of cell-phone bans. A Gallup poll last year indicated that 71 percent of drivers support bans on the use of hand-held phones while driving. Anderson added that his organization's polling reflect a similar level of support.

"The public strongly wants a ban on the use of hand-held cell phones while you're driving," he said.

At the same time, Anderson added that the rush to legislate cell phone use has not gotten to "the heart of the distracted driving issue."

"We're putting more and more instruments into cars, whether it's global positioning systems or TVs or VCRs, at a time when we're becoming much more congested on our highways. With the additional congestion and additional pedestrian population, you can't afford to be inattentive," he said.

Although some laws address distracted driving in general, the trend in proposed legislation has clearly been focused more on cell phone use. Cohen said that is because driving while on the phone is "something that has caught the public's attention, partly because it's a new form of distraction. It's something that’s visible. Very often you can't see if someone's fiddling with the radio, but you can see if someone's on the phone."

Enforcing the cell phone ban would be an additional responsibility for law enforcement officers, but experts disagree whether it would prove to be a burden or a useful tool.

Cell phone bans are "extremely difficult for police to enforce. It's really very hard to ask police to do an additional thing at a time when police resources are already stretched. We have bigger fish to fry and we're hesitant to give law enforcement another unfunded mandate," Adkins said.

Anderson argues that these bans serve an important function even if they are hard to enforce. "We have a lot of traffic laws on the books that are difficult to enforce, but they still serve as a deterrent and that alone can change a percentage of behavior."

Since New York's law went into effect, law enforcement officers have issued more than 140,000 tickets.

On the federal level, Sen. John B. Corzine, D-N.J., proposed legislation last year to prohibit driver use of hand-held phones, but it has not moved out of committee and it is not expected to. About 40 nations, including much of Europe, restrict or ban the use of cellular phones while driving.

"It's clear that it's something that has caught the attention of legislators, but I find it interesting that only one state has taken action so far," Cohen said.