New Jersey has become the first state to pass a law against driving while drowsy. Under Maggie's Law, police will not pull over drivers falling asleep at the wheel. But the law allows prosecutors to charge a motorist with vehicular homicide, punishable by up to ten years in prison and a $100,000 fine, in the event of a deadly crash if there is evidence the accident was caused by sleepiness.

No driver has yet been charged under the law, which went into effect last month and was named for a 20-year-old college student killed in 1997 by a van driver who admitted having been up for 30 hours.

Studies estimate 51 percent of motorists feel drowsy behind the wheel, and about one of every five drivers say they have fallen asleep while driving in the past year.

"We are so accustomed to being fatigued and tired and sleepy that it's part of our daily life and we think nothing of getting behind the wheel and driving despite the horrible ramifications of that act," said Marcia Stein of the National Sleep Foundation, a nonprofit research organization.

Safety advocates expect the New Jersey law will lead prosecutors to consider sleep deprivation when investigating accidents and will push other states to crack down on sleepy driving the way many did against drunken driving two decades ago.