Drowsy Driving: Why It’s Not Worth the Risk

This content was created by the National Sleep Foundation


Learn about what makes you tired behind the wheel—and how to perk up.

The expanse of the wide-open road. The monotony of highways that all look alike. That same song on the radio again. Driving—especially for long stretches by yourself—can be a recipe for drowsiness, especially if you’re already sleep deprived.

But sleepiness behind the wheel is not just an annoyance to be brushed aside or a challenge to be powered through. When you’re tired, your reaction time is delayed, which can lead to potentially deadly accidents. In the U.S., drowsy driving triggers at least 100,000 crashes a year, injuring 40,000 people and causing over 1,500 deaths.

Though most of us wouldn’t brag about getting behind the wheel drunk, 55 percent of Americans admit to driving while drowsy. And the truth is: The two are not so different. Shortchanging your sleep by just a few hours a night can add up to driving like someone who has had too many cocktails. And after just one sleepless night, your reaction time is similar to someone with a blood alcohol level of 0.10 percent. The scary difference: Whereas a drunk driver is slow, if you fall asleep at the wheel—even for a few seconds, into what's called a “microsleep”—you might not even brake or swerve, making the chances of a deadly crash even greater.

While late-night driving when your body is naturally fighting off sleep is the most risky, regularly snoozing too little can put you in dangerous territory anytime you’re behind the wheel. Check out some of the most common risk factors for drowsy-driving accidents—and what you can do about it.

Driving at Night

It’s not surprising that driving when your body thinks it should be sleeping is fighting a losing battle. Most accidents happen between midnight and 8:00am. To avoid this, either schedule your road trip during daylight hours, or, if you must travel at night, make sure to get plenty of sleep ahead of time.

Hitting the Road Solo

Driving alone doesn’t just feel harder—it is harder. There’s no one to talk to, no one to share driving duties with, and no one to call you out on the telltale signs of drowsy driving, like yawning, ending up too close to cars in front of you, or drifting into another lane. It’s also riskier. Some 82 percent of drowsy-driving crashes involve a single driver.

Having Anything to Drink

Sleepiness plus alcohol is a dangerous combination—potentially more deadly than either one alone. And it doesn’t take much to drink to tip the balance. Just one beer on four hours of sleep is equivalent to six beers for a well-slept person.

Driving After a Night Shift (or Cross-Country Trip)

Messing with your body clock by working through the night or traveling across time zones can make you vulnerable to nodding off behind the wheel. You may not be able to change your schedule, but incorporating regular rest periods, taking exercise breaks, and using bright lights can help re-set your circadian rhythms. Keeping a regular schedule, if possible, can also help you to maintain healthier sleep habits and stay safe on your commute.

Feeling Invincible

Rolling down the windows, sipping that extra-large coffee, cranking the music—you might think that these tricks can keep you awake, but there’s no evidence that they actually help. And while the “rumble strips” that alert you if you drift too far onto the shoulder can help, they won’t help if you drift into the other lane of oncoming traffic. If you feel yourself becoming drowsy (one telltale sign: You can’t remember the last few miles you drove), your best bet is to pull over and take a 20-minute power nap. After all, it’s better to arrive alive, even if you're late.