Most people have probably felt a little bit drowsy while driving their cars at some point.
According to the National Sleep Foundation, 51 percent of America's drivers feel sleepy, at times, when they're behind the wheel. And, as The Early Show Correspondent Melinda Murphy reports, drowsy driving is an all-too-common cause of crashes.
The Sleep Foundation's 2002 Sleep in America poll also showed that 20 percent of drivers, or about 32 million people, admit to having actually fallen asleep while driving in 2002. Many of them must live with the consequences for the rest of their lives.
Tom Callaghy and his wife, Jane, were on their way home from a competition with their dogs in April 2001 when their van crashed, flipping upside-down.
Tom wasn't hurt. But he says, "Janie's arm was lying on the ground in front of me. I could just barely reach it. And there was no sound from her. I couldn't tell whether she was breathing. So I reached out to check her pulse. And I didn't find any pulse."
Jane was dead, killed by a man who had fallen asleep while driving. That man was Tom. Drugs and alcohol weren't involved, and he wasn't speeding.
"We've all gotten drowsy while driving as I had, and you get through it. It's that belief that you're gonna get through it again - that kills."
Carole McDonnell's 20-year-old daughter, Maggie, was also killed by a drowsy driver. "He hadn't slept for 30 hours," she says. "He knew he was too tired to drive. He had a choice. He chose to take a risk. He could have pulled over at that point. He chose not to. Finally, he crossed three lanes of highway and hit Maggie and killed her.
"My other three children lost their baby sister. Her boyfriend lost the love of his life. He put a diamond ring on her finger as she lay in the coffin. All her friends were devastated. My husband had a stroke after he identified her body. Nobody's life is the same after this."
Drowsy drivers cause more than 100,000 crashes a year, according to the National Highway Traffic Safety Administration. Those crashes leave more than 1500 people dead and 70,000 hurt.
However, says the National Sleep Foundation's Darrel Drobnich, "We believe those numbers are greatly underestimated, and the true number could be 3 or 4 times higher than that."
He has studied the results of sleep deprivation driving tests: "After 24 hours of being awake, a person actually had the same impairment as someone who's...legally drunk in all 50 states."
Other tests show that fatigue is indeed an impairment, points out correspondent Murphy. "When you're tired, your brain crashes, and your vehicle might crash, too," she says.
"When you're behind the wheel of a car, it is a 3,000-pound killing machine, and if you are not fully alert, you can either kill someone else, kill yourself or do jail time," says the Sleep Foundation's Drobnich.
But jail time is far from automatic, as Maggie's mother, Carole, learned. The drowsy driver who caused the crash that killed her daughter "received a moving violation, a $200 fine and a suspended 6-month sentence. …If you hit a tree, you would have received the same punishment."
So Carole set out to change the law. In August of 2003, "Maggie's Law" was signed in New Jersey - making it the only state in the country with a drowsy driving law. It says that if you're awake more than 24 hours, then drive and kill someone, you can be charged with vehicular homicide. It's considered recklessness in the state of New Jersey.
The law wouldn't have applied to Tom, who had slept seven hours the night before his crash. But, he says, that doesn't ease the guilt he lives with: "I'm responsible for the death of somebody else. And that's pretty hard to take."
Others may follow New Jersey's lead, Murphy reports. A bill before Congress would give states financial incentives to adopt drowsy driving measures.
Proving drowsy driving could be difficult, Murphy notes. There aren't technologies like breathalyzers for that yet.
But there are telltale signs, such as no skid marks at the scene of a crash. And investigators could check into how much sleep a crash-causing drowsy driver got in the 24 hours before the incident.
A common misconception, Murphy notes, is that turning on the radio at high volume or rolling down a window can helt make a drowsy driver more alert.
The only effective countermeasures, she says, are taking a nap and ingesting caffeine.