A study conducted by researchers at Virginia Tech reported that 20 percent of all accidents have sleepiness as a contributing factor [source: TheDenverChannel]. If a driver is tired enough to actually fall asleep while driving, the results are predictable. Even on a relatively straight highway, a sleeping driver will eventually drift off the road. Trees, utility poles, ravines and bridge abutments turn this into a deadly scenario -- and that doesn't even take other cars into account.
You might think a few yawns are nothing to worry about, but just being a little drowsy is enough to increase your risk of getting in an accident. Responses can range from dozing off for a few seconds at a time to simply "zoning out" and losing all focus on the road. At highway speeds, one or two seconds of inattention can lead to disaster.
The solution is simple: Get a better night's sleep! Make sure you get a solid eight hours of sleep, not just on the night before a long drive, but on a regular basis. Failure to get enough sleep every night builds a sleep deficit that can leave you drowsy and unable to focus. If you're driving and feel the least bit groggy, take action immediately. Don't think you'll get any kind of warning before you fall asleep, or that you can fight it off. People can move from drowsy to sound asleep without warning. If this happens to you, have a friend take over behind the wheel, find a rest area where you can catch a few hours of sleep or take a break until you're feeling more alert.