Drowsy Driving

Drowsy driving or fatigued driving is another extension of distracted driving and is comparable to impaired driving. Drowsy driving occurs when a person operates a motor vehicle when too fatigued or sleepy to stay alert, making the driver less aware of their surroundings. After 17 consecutive hours awake, impairment is estimated to be equivalent to having a blood alcohol content (BAC) of .05 and after 24 hours awake, impairment is estimated to be equivalent to a BAC of .10.¹ A survey of the U.S. workforce found that approximately 37% of workers get less than the recommended minimum of 7 hours of sleep per night which may contribute to their drowsiness.²

Driver fatigue has been associated with being awake for too many consecutive hours, not getting enough sleep over multiple days, monotonous tasks or long periods of inactivity, and health factors such as sleep disorders or medications that cause drowsiness. Fatigue impairs a driver's ability to safely drive a vehicle by causing the driver to nod off; react more slowly to changing road conditions, other drivers, or pedestrians; make poor driving decisions; drift from their travel lane; lose sense of what’s going on in their periphery; experience brief sleep episodes lasting from a fraction of a second up to 30 seconds; and forget the last few miles driven.

While there are regulations that set maximum numbers of driving and work hours specifically for driving vehicles that require a commercial driver’s license, workers in many other jobs are at risk of driver fatigue. It is incumbent upon employers and drivers to recognize and prevent excessive driving and work hours that contribute to drowsy driving.

Additional Information

National Highway Traffic Safety Administration (NHTSA)

NIOSH Driver Fatigue