© Westend61 via Getty Images Tired man driving car Westend61 via Getty ImagesYou wouldn't drink and drive. But what about yawn and drive?

Data shows that operating a vehicle when you're exhausted is just as dangerous as drunk driving -- and it occurs rather frequently. An estimated 1,550 people die each year from drowsy driving accidents. Not. Worth. It.

If you're too tired to function -- especially behind the wheel -- it can be incredibly risky to take the road for both you and other people. Below are a few signs you may be too drowsy to drive, and expert-approved advice for what to do instead.

You haven't slept.

All nighters are especially a no-no, according to the National Sleep Foundation. Be realistic about your alertness. The recommended amount of sleep is around seven to nine hours, but if you're still lagging, it's better to be safe than sorry.

You've been driving a long time.

Driver fatigue can happen very easily on long drives and road trips, Nathaniel Watson, president of the American Academy of Sleep Medicine, told The Huffington Post. Be aware of the amount of time you've spent behind the wheel and make alternate arrangements if necessary.

You're cranky.

You may believe you racked up enough Z's, but you can tell a lot about your level of sleep deprivation based on your mood. A recent study found that those who didn't get an adequate amount of sleep were less able to regulate their emotions, causing them to overreact to everyday challenges they would otherwise take in stride. Road rage, anyone?

You don't remember the last few miles.

Did you pass a landmark? What exit are you near? Short-term memory loss or a lack of awareness about your surroundings is a glaring sign you're probably too tired to drive, Watson said. 

You're drifting.

Difficulties concentrating or weaving in and out of lanes isn't just a sign of drunken driving. "If you have trouble focusing your eyes on the road, or difficulty steering straight or steady, you are likely to tired to drive," said David Davila, a board member of the National Sleep Foundation. 

So what do you do about it?

Driving is pretty much inevitable in the day-to-day lives of many of us. Here's how to minimize the effects of sleepiness and transportation:

• Prioritize your sleep. The right amount of Z's should be a top health goal, says National Sleep Foundation environmental fellow Natalie Dautovich. From maintaining a regular sleep schedule to making sure you're sleeping in a cool, dark room, it's important to adjust your behavior accordingly. Lifestyle habits, like consuming too much caffeine and alcohol late in the day, can also disrupt sleep, she explained. 
• Take breaks. If you're feeling snoozy on the road, give yourself some rest. This is especially applicable if you're on a long trip. "Try to find a safe location to stop driving, drink a caffeinated drink and take a 10-20 minute nap," Davila said. "It will take about 30 minutes for the caffeine to take effect."
• Know that distractions don't work. And they shouldn't be used as a substitute for breaks if you're cruising when you're tired. "Rolling down the windows or turning up the volume on the radio will do little to increase your alertness while driving," Watson advised.
• If you can avoid it, don't get behind the wheel.  This is especially true if you didn't get a good night's rest and you can't keep your eyes open. Nothing is worth potentially putting your life -- or someone else's -- at risk, Watson says. "At the end of the day, there's no substitute for sleep," he stressed.