And now we have a special experiment to show you. What happens when you think you're awake behind the wheel but your brain is going to sleep? Drowsy driving is so serious in this country, there are now criminal cases in half a dozen states threatening jail time for people accused of being too sleep deprived to drive. Abc's ron claiborne wants to show you what happened to him. Reporter: My eyes are open but what you can't tell in this experiment, I'm actually asleep. Every day an estimated 250,000 americans fall asleep while driving. Like this woman who was videotaped seemingly nodding off at the wheel in denver. Sleep deprived drivers are blamed for thousands of crashes every year. But many times it's not that obvious. Scientists say there's something called micro sleep where you can fuel asleep for just a few seconds without realizing it. Sometimes with your eyes open. Hi, I'm ron claiborne. We traveled to the liberty mutual research institute outside of boston where they study it. Micro sleep is a transition from wakeful ins to sleep and it can last up to maybe 20 or 30 seconds. You're awake and suddenly asleep. Reporter: I agreed to take part in an experiment. I would drive while sleep deprived. To mimic the condition I stayed up all night. Up to close to 48 hours. Reporter: I was hooked up to a brain wave monitor. I thought I could handle the driving. I feeling 0 now and got behind the wheel of a men very van. Feeling pretty worn out. My eyes are open but I'm asleep and here too. This is what micro sleeping can look like. At one point I did dose off. That was not good. Finally -- doc, I'm done. I know I had dosed off a couple of times but what was stunning i had actually micro slept 22 times and never knew it so what was going on inside my brain? This is evidence that you're falling asleep. My eyes were open but see how these lines are becoming more jagged. That's sleep coming on and these lines show my blinking is getting slower. I microslept for three seconds. If I had been driving 60 miles an hour I would have gong the length of a football field asleep. I was in a real twilight zone the entire time. And it was scary. 22 times you dozed off. I remember two. You only remember two. What a lesson this is. What about caffeine, you lower the windows and put on the music. I asked the experts that. Turning up the music, putting down the window, yelling to yourself, that doesn't work. Caffeine will stave off the sleep for awhile. But only for awhile. It is not an antidote or the solution. Is there a specific signal that lets you know your brain is going to sleep. That's the insidious thing about this. There is no way of knowing. No way of predicting you'll be too tired. If you are tired, you are too tired, get off the road. Take a nap, do not drive. And, again, hundreds of thousands of people are out there on the road with this. Thanks so much, ron. And coming up next, you