We’ve all been there — it’s the end of a long road trip; you’re ready to be home, it’s late at night and the freeways are wide open. The passengers in your car are all asleep, snoring soundly as you desperately try to stave off the drowsy feeling setting in and the steady droop of your eyelids. It’s driver fatigue, and it’s potentially a very deadly situation.

Driving On No Sleep Is As Dangerous As Driving Drunk

Everyone knows what a bad idea it is to get behind the wheel if you’ve had anything to drink. It goes without saying that doing so would be an idiotic, irresponsible thing for anyone to do, and instantly puts the driver and everyone else on the road in mortal danger. We all agree on that, yet we are all much more likely to do something that is arguably just as dangerous: drive on too little sleep.

AAA estimates that about 21% of all car crashes that involve fatalities involve an instance of driver drowsiness where lack of sleep played a direct role in the accident. That’s a shocking number, and it’s worth realizing that that number involves thousands of innocent lives lost because someone misjudged their ability to safely react to what was happening on the road.

The magic number appears to be about 7 hours. If a driver has received at least that much sleep in the prior 24 hours, they are generally considered not to be at risk for drowsiness-related impairment behind the wheel. Those who had 5-6 hours saw their risk increase twice over; while those who had four hours or less have a whopping 12x likelihood of a catastrophic crash.

What Is Driving Vigilance?

We all drive every day quite a bit, especially those of us in Los Angeles. With so many hours logged behind the wheel, it’s all too easy to start feeling overconfident about your abilities to navigate the roads and safely operate your car, even in less-than-optimal conditions. Yet, we forget that when accidents happen, it’s often because something unexpected occurred in a split second on the road, and one or more drivers were not able to react quickly enough. Lack of sleep severely inhibits your reaction time, which can make all the difference in responding to an unplanned event on the road.

There are things you can do to increase your driving vigilance, or alertness behind the wheel, if you are feeling drowsy but need to complete your trip. First of all, consider taking a nap if at all possible. Even 15-30 minutes of shut-eye on the side of the road or at a rest stop can start to pay back some of the sleep deficit you have accrued. When you’re driving, play music on the radio, talk to passengers, open windows, and do what you can to maintain an alert state. Consider drinking a caffeinated beverage like coffee, if you know it’s safe for you to do so.

And don’t forget — you can always pull over and rest until you’re ready to safely drive. Your destination will still be there for you when you wake up.