You’d never slide behind the wheel after too much to drink, but what about after too little to sleep? Skimping on sleep can be just as risky on the road as driving drunk can be, new research from the AAA Foundation For Traffic Safety shows.
The study analyzed more than 7,000 car accidents over 29 months, and assessed how many hours the driver had slept in the 24 hours preceding the crash. The researchers discovered that drivers who slept between 5 to 6 hours had nearly double the crash risk as those who slept for at least 7 hours.
And those who slept less than 4 hours had almost 12 times the crash risk—that’s comparable to that of a drunk driver with a blood alcohol concentration (BAC) of 0.12-.015, well over the .08 BAC legal limit in the United States.
Plus, missing out on your normal sleep can be dangerous, regardless of how many total hours you end up snoozing for. For example, people who logged 1 to 2 hours less sleep than usual were 30 percent more likely to contribute to a crash than those who slept their normal amount. And those who skipped 2 to 3 hours from their usual were 3 times as likely to cause an accident.
Driving is a vigilance-based task, meaning you need the ability to monitor, react, and pay attention to do it successfully, says David F. Dinges, Ph. D., chief of the division of sleep and chronobiology at the University of Pennsylvania School of Medicine.
These abilities deteriorate with inadequate sleep—the study shows you’ll likely notice deficits with as little as an hour or two of less sleep. And the more sleep you miss, the more severely your abilities will be compromised.
Driving when you’re sleepy is never worth it, and people are notoriously bad at judging how likely they are to actually doze off, he says.
In fact, it takes most people between two to four minutes before they can “wake up” and realize they were asleep—a dangerous amount of time when you’re on the road.
So splurge on a cab or take an Uber instead, he says. But if there’s no choice and you absolutely must drive, follow the following tips.
- First, see if you can hold off on your trip for a bit. That’ll give you time to nap. Longer is better, but even 20 minutes has been shown to begin re-establishing vigilance, says Dinges.
- Then, after your nap and before heading out, drink something with caffeine in it. This will help fight what researchers call sleep inertia—the groggy feeling you get after a nap.
- If you have anyone in the car with you, keep a conversation going to ensure you don’t accidentally drift off, Dinges says. Finally, stop every two hours or every 160 kilometres at rest stop, and build them into your road trip schedule so that you’re more likely to actually stop, and use that time to recharge with a quick nap, to switch drivers, or take a quick walk to boost your alertness.
By Diana Stanczak