Falling asleep behind the wheel may happen more often than you think.
The Centers for Disease Control and Prevention says drowsy driving is a growing problem. One in 24 drivers reported they had dozed off while driving in the last month.
The CDC's Ann Wheaton says the number is probably higher because many drivers don't realize when they're nodding off for a second or two.
Even if you don't fall asleep, Wheaton says driving drowsy is like driving drunk.
"The prevalence of people actually driving while impaired by being sleepy, is going to be a bit higher," Wheaton tells CBS. "Sometimes people will fall asleep for just a moment and not realize they had fallen asleep."
The research found that men were more likely to fall asleep behind the wheel and the problem is more prevalent among drivers between the ages of 25 and 34.
More and more, Wheaton says, people are burning both ends of the stick and are getting less than six hours of sleep.
"Some previous studies have shown that being awake for 24 hours, is comparable to blood alcohol level of 0.1 percent, which is above the legal limit in all states."
The state with the most drivers nodding off is Texas; Oregon had the fewest.
The AAA Foundation estimates that tired drivers were responsible for one in six fatal crashes, and one in eight accidents that sent someone to the hospital. In more than half the accidents, sleepy drivers drifted into another lane or off the road entirely.
Warning signs you're driving drowsy? Not remembering the last mile or two, or drifting onto rumble strips on the side of the road. Even if you nod off for a second or two, that could be extremely dangerous at 60 miles an hour one second translates to speeding along for 88 feet, the length of two school buses.