You open the windows for fresh air. You pass a familiar landmark and can't remember driving the last five miles. You crank the volume on the car stereo, but it doesn't help. Sleep, however, is winning the battle. You're startled by the sound of your tires hitting the rumble strips on the side of the road.
Some drowsy drivers have the good fortune to regain control of their cars.
Others aren't so lucky. The National Highway Traffic Safety Administration estimates that sleepy drivers cause at least 100,000 motor vehicle crashes each year. According to the National Center on Sleep Disorders Research, fall-asleep crashes are likely to be more serious, possibly due to high speeds and the driver's delayed reaction time. In 1996, the AAA Foundation for Traffic Safety surveyed 101 members of the National Trooper Coalition for Traffic Safety and found that a drowsy driver is actually more dangerous than a drunk driver. A drowsy driver may never see the traffic light.