Legally Easy

Extensive research shows the dangers of distracted driving. Studies say that drivers using phones are four times as likely to cause a crash as other drivers, and the likelihood that they will crash is equal to that of someone with a .08 percent blood alcohol level, the point at which drivers are generally considered intoxicated. Research also shows that hands-free devices do not eliminate the risks, and may worsen them by suggesting that the behavior is safe.

In 2003, researchers at a federal agency proposed a long-term study of 10,000 drivers to assess the safety risk posed by cellphone use behind the wheel. They sought the study based on evidence that such multitasking was a serious and growing threat on America’s roadways. But such an ambitious study never happened. And the researchers’ agency, the National Highway Traffic Safety Administration, decided not to make public hundreds of pages of research and warnings about the use of phones by drivers — in part, officials say, because of concerns about angering Congress.

On Tuesday, the full body of research is being made public for the first time by two consumer advocacy groups, which filed a Freedom of Information Act lawsuit for the documents. The Center for Auto Safety and Public Citizen provided a copy to The New York Times, which is publishing the documents on its Web site. In interviews, the officials who withheld the research offered their fullest explanation to date.

The former head of the highway safety agency said he was urged to withhold the research to avoid antagonizing members of Congress who had warned the agency to stick to its mission of gathering safety data but not to lobby states.

Critics say that rationale and the failure of the Transportation Department, which oversees the highway agency, to more vigorously pursue distracted driving has cost lives and allowed to blossom a culture of behind-the-wheel multitasking.

“We’re looking at a problem that could be as bad as drunk driving, and the government has covered it up,” said Clarence Ditlow, director of the Center for Auto Safety. The group petitioned for the information after The Los Angeles Times wrote about the research last year. Mother Jones later published additional details.