Other contributing factors include sleep disorders such as sleep apnea and insomnia, Wheaton said.
In 2009, approximately 30,000 people were involved in car crashes due to drowsy driving and 730 died, according to the U.S. National Highway Traffic Safety Administration.
Drowsy driving also varied state-to-state, from a low of 2.5 percent in Oregon to a high of 6.1 percent in Texas, the report found.
The findings were based on a survey of almost 150,000 drivers.
The best way to prevent drowsy driving is to get at least seven hours of sleep. And people with a sleep disorder should seek treatment, the CDC said.
The agency also recommends not drinking alcohol or taking sedatives before sliding into the driver's seat.
Wheaton said some of the signs of drowsy driving include: not remembering the last couple of miles driven; missing an exit on a highway; having trouble staying in a driving lane; and struggling to keep your eyes open.
"If you have these symptoms you need to get off the road and rest until you're not sleepy anymore," she said. "Even better is to change drivers with someone who is not sleepy."
Russ Rader, a spokesman for the Insurance Institute for Highway Safety, said: "Drowsy driving is a lot like distracted driving -- it's not something you can outlaw and solve the problem. Technology may help. High-tech, crash-avoidance systems can alert drivers to hazards or even take action autonomously if your attention wanders or you're sleepy and may prevent a lot of crashes in the future. These systems are always on alert and never get tired like people do."
For more on driving while drowsy visit the AAA Foundation for Traffic Safety.
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