As clocks “fall back” this week, the shift in daylight hours can throw off your sleep schedule and your alertness behind the wheel. Losing even a little sleep or disrupting your routine can make you feel more tired than usual, increasing your risk of drowsy driving.
According to a 2025 survey from the American Academy of Sleep Medicine, 41% of U.S. adults have felt so sleepy while driving that it affected their ability to drive safely. That includes half of men (50%) and one-third of women (33%).
Drowsy driving is like driving drunk
Drowsy driving is a serious health and safety risk, and like drunk driving, it is completely avoidable. When you don’t get enough quality sleep, your brain doesn’t function at full capacity. Fatigue slows reaction times, reduces alertness, and makes it harder to stay focused on the road.
Even moderate sleep loss can affect driving ability in ways similar to alcohol.
One study found that after 17 to 19 hours without sleep, performance was equal or worse than driving with a blood alcohol concentration of 0.05%. Response speeds were up to 50% slower, and accuracy dropped significantly. After longer periods without sleep, performance declined to levels comparable to a BAC of 0.1%, which is higher than the legal limit for driving in all U.S. states.
Just as alcohol impairs judgment and coordination, drowsiness can delay reaction times and make it harder to respond quickly behind the wheel.
The AAA Foundation for Traffic Safety estimates that about one in six fatal crashes involves a drowsy driver. Drivers between ages 35 and 44 were the most likely to report feeling so tired at the wheel that it impaired their ability to drive safely, but anyone can experience the effects of fatigue.
Warning signs to watch for
You might not realize how drowsy you are until it’s too late. Warning signs include:
- Frequent yawning or inability to keep your eyes open
- Catching yourself “nodding off” or having trouble keeping your head up
- Inability to remember driving the last few miles
- Missing road signs or driving past your turn
- Following too close to cars in front of you
- Drifting into the other lane of traffic
- Driving onto the “rumble strip” or the shoulder of the road
If any of these sound familiar, it’s time to pull over or have another passenger take the wheel.
How to stay alert
Before driving, make sure you’re well rested. The AASM recommends that adults should sleep seven or more hours per night on a regular basis. Avoid driving late at night or alone when possible, and share driving duties on long trips. If you start feeling drowsy, stop at a rest area and take a short nap.
If you work late or overnight shifts, arrange for a ride home instead of driving yourself.
Getting enough healthy sleep is one of the most effective ways to reduce the risk of drowsy driving.
Learn more about healthy sleep habits or find an AASM-accredited sleep center near you.