LOS ANGELES (KABC) -- More than one in five fatal crashes on U.S. Roadways are caused by drowsy drivers, according to officials.
An hour or two of missed shut eye is enough to cause deadly consequences, and AAA said you can't lose sleep and expect to function safely behind the wheel.
Government health officials said more than a third of drivers out on streets and highways were tired enough to contribute to a crash.
Whenever you get behind the wheel, chances are people sharing the road with you may not have had a good night's sleep.
The CDC said 35 percent of U.S. drivers sleep less than the recommended seven hours daily.
New findings from the AAA Foundation for Traffic Safety warned that drivers getting less than seven hours of sleep could have deadly consequences.
The data revealed drivers who got less than seven hours of sleep in a 24 hour period doubled their risk of crashing.
"If you get less than five hours, you almost quadruple the risk of crashing," said Jeff Spring from the Automobile Club of Southern California.
Less than four hours means you'll be 11 times more likely to contribute to an accident.
Researchers studied police-reported car accidents, but did not take alcohol or drug use into account.
Previous studies have shown driving drowsy is similar to driving while under the influence.
"You're having decreased attention span, low alertness, other symptoms that put you in the same category and could cause the same results as a drunken driver," Spring said.
Getting to bed at a consistent time, limiting caffeine late in the day and turning off screens an hour before bed can help you get your recommended seven hours of shut eye.
If you didn't get enough sleep and are behind the wheel, AAA recommends taking frequent breaks.
"If you're driving a long distance you want to try to plan stops every two hours or about 100 miles or so just get out of the car, walk around," Spring explained.
More tips from the Automobile Club include:
- Travel at times when normally awake.
- Avoid heavy foods.
- Travel with an alert passenger and take turns driving.
- Avoid medications that cause drowsiness or other impairment.
Another AAA report found 97 percent of drivers surveyed said they strongly oppose drowsy driving. Yet, one in three admitted they've done it.
Less than 7 hours of sleep doubles chance of car crash, study says