A study released this week by the Centers for Disease Control and Prevention may have the weary thinking about getting some rest before they get behind the wheel. The study found that one in 24 U.S. adults said they recently fell asleep while driving.

The National Highway Safety Administration estimates 2.5 percent of fatal motor vehicle crashes (about 730 in 2009) and 2 percent of all crashes with non-fatal injuries (about 30,000 in 2009) involved drowsy driving, according to the CDC.

“However, although data collection methods make it challenging to estimate the number of crashes that involve drowsy drivers, some modeling studies have estimated that 15 to 33 percent of fatal crashes might involve drowsy drivers,” the report stated.

In the study, about 4 percent of U.S. adults said they nodded off or fell asleep at least once while driving in the previous month. The study surveyed 147,000 people in 19 states by telephone in 2009 and 2010.

Researchers found that drowsy driving was more common among people ages 25 to 34, adults who reported usually sleeping six hours or less per day, snoring or unintentionally falling asleep during the day.

Steve Deibel, owner and founder of Aiken Driving Academy, said that a section of his classes address fatigued driving. He shows students a video on a New Jersey law known as “Maggie’s Law.”

The law was enacted following an accident in 1997, during which college student Maggie McDonnell was killed in a car accident when struck by a van driven by someone who had not slept for 30 hours and had also been using drugs. The driver fell asleep at the wheel when the accident occurred.

After two trials, the driver of the van was given a $200 fine and a suspended jail sentence. The law defines fatigue as being without sleep for more than 24 consecutive hours and makes driving while fatigued a criminal offense.

“We show that video and talk to our young people about fatigue,” Deibel said. “They’re tired because they stay up late. They get six or eight hours of sleep at night but need 10 to 12.”

Deibel, a former law enforcement officer, said there have been fatalities in Aiken County related to fatigued driving.

“It’s very overlooked, and it’s very serious,” he said. “You’ve got to have rest. You can’t be on the road when you’re tired or fatigued.”

Deibel said the video also followed a news reporter that was kept awake for 30 hours as part of an experiment. He then was hooked up to monitoring machines and drove a car on a closed course.

“What came of the study – you fall asleep but your eyes are open,” Deibel said. “Our bodies are built to shut down. If you have somebody that’s fatigued behind the wheel and they’re essentially asleep, you might as well just blindfold them.”

Deibel said falling asleep at the wheel is as dangerous as driving 2.5 times the legal blood-alcohol limit.

“I hate making those correlations, because impaired driving is extremely dangerous,” he said. “I think you have to lump fatigued driving into all the serious dangers of driving. You can’t look at it as, ‘I’m sleepy. I’ll just get some coffee.’”

If you feel fatigued while driving, Deibel suggests pulling over, getting out of the vehicle and getting something to eat, especially if you find yourself rubbing your eyes, rolling down the window, turning on the air conditioner or doing other things to keep yourself awake.

“If you start doing things to stay awake, you need to stop and look at your sleep cycle,” he said, adding that if the last time you slept was more than 18 to 20 hours, you don’t need to be driving.

He added that fatigued driving, as opposed to “tired driving,” usually occurs after being awake for 18 hours or more.

If you’ve been awake 18 hours or more, “you need to start looking very hard at where you’re driving, when you’re driving and if you need to be driving,” Deibel said. He added that caffeine is only a temporary fix in some cases.

“How much caffeine does it take to keep somebody awake who’s been awake for 20-plus hours?” he said. “It eventually wouldn’t, because your body is just going to shut down.”

Teddy Kulmala covers the crime beat for the Aiken Standard. He is a graduate of Clemson University and hails from Williston.