Sleep deprivation: Lack of sleep is a leading cause of excessive daytime sleepiness, which can induce microsleeps or other dangerous driving behavior. Adults should get between seven and nine hours of sleep each night, but a significant number of adults routinely fail to get this recommended amount of sleep.
Sleep disorders: Many sleep disorders, such as obstructive sleep apnea, cause a person’s sleep to be restricted, interrupted, and less restorative. Many sleep disorders go undiagnosed and, when left untreated, can cause daytime drowsiness.
Alcohol: Drinking alcohol can prompt sleepiness while also affecting reaction time and decision-making in ways that increase the risks of auto accidents.
Medications: Numerous medications cause sleepiness. Sleep aids, including prescription drugs, over-the-counter medications, and dietary supplements, that are taken at night may cause lingering grogginess the next morning. Drowsiness is also a side effect of medications used for many other conditions.
Time of day: Auto accidents from drowsy driving occur most frequently between midnight and six a.m. or in the mid-afternoon, which are two times when sleepiness peaks.
STATS
More than half of U.S. adult drivers admit to consistently getting behind the wheel while feeling drowsy.
About 37% admit to falling asleep behind the wheel, while 13% admit to falling asleep behind the wheel in the past month.
Losing even two hours of sleep is similar to the effect of having three beers.
The crash risk for driving on 4-5 hours of sleep is more than 4 times higher than someone who has slept 7 hours, which is the same crash risk as a drunk driver with a 0.08 alcohol concentration.
Twenty-one percent of fatal crashes involve a drowsy driver.
More than 6,400 fatal drowsy-driving crashes occur annually.
People are three times more likely to be in a car crash if they are tired.