Falling asleep at the wheel is clearly dangerous, but being sleepy affects your ability to drive safely even if you don't fall asleep. Drowsiness:
•Makes drivers less attentive
•Slows reaction time
•Affects a driver's ability to make decisions
The Scope of the Problem
Although it may be difficult to attribute a fatal vehicle crash to drowsy driving, the National Highway Traffic Safety Administration estimates that 2.5% of fatal crashes and 2% of injury crashes involve drowsy driving. These estimates are probably conservative, though, and up to 5,000 or 6,000 fatal crashes each year may be caused by drowsy drivers.
Who's More Likely to Drive Drowsy?
•Shift workers (work the night shift or long shifts)
•Drivers with untreated sleep disorders such as sleep apnea
•Drivers who use sedating medications
•Drivers who do not get adequate sleep
How Often do Americans Fall Asleep While Driving?
Among nearly 150,000 adults aged at least 18 years or older in 19 states and the District of Columbia, 4.2% reported that they had fallen asleep while driving at least once in the previous 30 days. Individuals who snored or usually slept 6 or fewer hours per day were more likely to report this behavior.