America's capital and two states - New York and New Jersey - ban the use of hand-held cell phones while driving, and 16 other states have enacted a broad spectrum of laws involving cell phone use while driving.
For instance, Delaware prohibits school bus drivers on duty from using cell phones and Maine prohibits cell phone use by drivers under 21 with a learners permit.
But no state has a complete ban on cell phone use by motorists, according to the National Conference of State Legislatures. And at least two states - Mississippi and Nevada - prohibit local jurisdictions from regulating cell phone use by drivers, even if the state has no restrictions.
"This is a pretty new issue," said Matt Sundeen, program principal in the transportation program of the conference of state legislatures.
"Ten years ago, hardly anyone had a cell phone. Now your car can have a TV, DVD player, [and] navigational system. There's a concern among legislators who are proposing these laws that this is another distraction that drivers can't handle," Mr. Sundeen said
Brooklyn, Ohio, a Cleveland suburb, banned driver use of hand-held mobile phones in 1999, the first U.S. municipality to do so.
North Olmsted and Walton Hills in Ohio now have similar ordinances.
Michigan has no such local laws, according to the conference of state legislatures, and neither Ohio nor its northern neighbor has statewide laws restricting cell phone use by motorists.
Data so far suggest that cell phone use causes a low number of accidents, but "there [are] studies both ways on the issue," Mr. Sundeen said.
Some studies suggest that the primary problem is "cognitive distraction" - when the driver's mind is not on driving - rather than physically holding something, he said.
That distraction could be as simple as conversing with a passenger.
The Oregon legislature in 2003 considered prohibiting drivers from doing anything distracting, such as responding to events, persons, or objects inside or outside the vehicle that are not related to the safe operation of the vehicle, but those provisions were not passed.
Still, legislators across the country have begun to deal with broader distractions, Mr. Sundeen said.
The same Washington law that bans the use of hand-held phones by motorists also makes reading and personal grooming illegal while driving.
"There's a lot of bizarre behavior on the road," Mr. Sundeen said. "It's a question of which ones are most distracting and you want to prohibit."