A new law that took effect this month in Maine bears watching as a strategy for cutting down on distracted driving.

But it's vague approach might create as many problems as it solves.

Instead of banning a particular activity -- text messaging, changing radio stations, eating messy sandwiches -- the law broadly targets anything that isn't "necessary" to operating a vehicle that impairs the ability to drive safely.

It doesn't give police a blank check to pull over any drivers they see chatting on the phone or eating pizza. Drivers still have to commit another violation or be involved in an accident before they can be ticketed for "distracted driving."

The theory behind it sounds good - target behavior that causes harm, not particular devices.

The practical application of the law might not be as simple.

Maybe that's why police in Maine say they will probably be issuing a lot of warning tickets at first. This is likely to be a learning experience for police as well as motorists.

Among the reasonable questions are: How will police know if a person was involved in some distracting activity while speeding, changing lanes improperly or getting in an accident? What kind of evidence will courts require before imposing additional fines for distracted driving?

Most important: Will a law this vague have much effect in changing people's behavior?

A ban on text messaging, like the one in Illinois that takes effect Jan. 1, is straight forward. It might not stop some people, but at least they know when they are violating the law.

Maine's law leaves people guessing.

Clearly, something must be done. Studies have shown that a distracted driver can increase the odds of an accident the same as a drunken driver. Maine officials estimate that about one-third of the state's 36,000 crashes annually involve drivers who were distracted.

Between electronic gizmos inside vehicles and flashing message boards outside, motorists have plenty of opportunities for distraction.

New ones seem to be added each day - who would have thought even 10 years ago that cars with satellite navigation systems would become fairly common? That's one argument in favor of Maine's broad-based law, instead of changing laws each time a new electronic device arrives to distract drivers.

Perhaps some answers will come from the distracted driving summit organized by Transportation Secretary Ray LaHood. Research data and legislative approaches are among topics on the agenda of the summit today and Thursday.

Most likely, a multi-pronged approach will be needed that combines regulation and education - something that will drive home the point that multi-tasking behind the wheel isn't a virtue; it's a danger.