Since LaHood's first summit on the subject a year ago, the number of states that ban use of handheld cellphones while driving has risen to eight and the number that prohibit text messaging has increased to 30. Legislation in Congress would dangle additional funding to states that ban both.

In what might be a turning point, the Governors Highway Safety Association (GHSA) will consider whether to endorse a complete ban on cellphone use while driving when it begins its annual meeting Sunday.

Though the GHSA is little known to the general public, endorsement of a total ban could prove pivotal in swaying the debate over the technology America has come to love and the risk it poses on the roadway. The GHSA, made up of state highway safety officials from across the nation, carries clout in the transportation community, and other groups could follow its lead.

The nonprofit National Safety Council is on record favoring a total prohibition. The council has estimated that cellphone use is responsible for 1.4 million crashes a year, about 28 percent of the national total.

Although LaHood launched his distracted-driving crusade with an attack on text messaging, he's not been shy about saying that all cellphone use is too dangerous to be tolerated.

"We've taken some baby steps," he said last week. "Now we have to take some giant leaps. This issue of distracted driving is as significant as drunk driving."

Drunk driving wasn't taken as seriously until Mothers Against Drunk Driving and highly publicized police crackdowns put people in handcuffs. Seat-belt use was minimal until the "Click It or Ticket" campaign. In the Washington region, the Smooth Operator crackdown has raised awareness that arrest is a consequence of aggressive driving.

One of the major questions about distracted drivers has been whether they would obey the law. Drivers know it's tough to spot them when they send text messages, and that most police forces are too busy to make catching them a priority.

"Whenever I'm driving around Washington, almost every car has a person with a cellphone to their ear," LaHood said, even though use of handheld phones while driving is banned in the District.

In Fairfax County, police frustrated by the ineffectiveness of a state law banning texting while driving recently announced they would use an old law requiring drivers to "pay full time and attention" to crack down on the practice. Police are also using sport-utility vehicles and trucks to help them look down into vehicles and spot violators. To see whether prohibitions could be effectively enforced, the federal government funded pilot programs in Syracuse, N.Y., and Hartford, Conn., states where texting and handheld use are banned. Each city sent additional officers out for two one-week periods to catch violators.

They found that it is relatively easy to catch someone who has a phone pressed to his ear and quite difficult to spot someone texting. In Syracuse, they issued 4,172 citations to cellphone violators and 284 to texters. The results were similar in Hartford.

"Some officers would sit somewhere above the road, looking down," said Capt. Shannon Trice, who heads the police traffic division in Syracuse. "They found that was the most success with texting, since most people do texting in their laps."

Although both cities counted the effort as a success, neither could afford to maintain the same level of vigilance once the federal funding expired.

"Unfortunately, the officers have other duties," Trice said.

Pointing to the seat-belt enforcement effort, he said police must bring the message home with enforcement whenever they can.

"It's going to take a long time," he said. "But every citation we give out, I'm sure that person tells 20 other people about getting it."

The American Automobile Association affiliate in Southern California concluded that police weren't doing enough after it conducted a roadside survey at seven locations.

The Automobile Club of Southern California found that 19 months after the state banned text messaging, the number of drivers doing it had almost doubled. The use of handheld phones, also banned, had remained unchanged.

The group said the California highway patrol issues an average of 200 texting citations each month, compared with 12,500 for handheld cellphone use.