When people drive while they are tired, drowsy, or sleepy, this is referred to as “driver fatigue.” Driver fatigue is a major cause of car accidents, since sleepy drivers are unable to make rapid decisions, and they may have slower reaction times. As a result, many governments have education programs to alert people to the dangers of driving while tired, and drivers are encouraged to avoid conditions which may lead to driver fatigue.
Tired drivers often have a difficult time processing and using information; for example, a driver may not recognize that he or she has drifted into the wrong lane until it is too late. Driving fatigue can also lead to reduced vigilance and slower reaction times. In extreme cases, a driver may actually fall into a microsleep, briefly losing consciousness on the road, and this can be extremely dangerous. The risks of driver fatigue go up dramatically between 10:00 PM and dawn, especially for people who work unusual hours or who may have sleep disorders.
A number of symptoms can suggest driver fatigue, including yawning, tired eyes, boredom, an inability to remember the last segment of the road, oversteering, restlessness, and difficulty concentrating. Drivers who notice these symptoms should pull over to rest, ideally getting out of the car and stretching as well. Many major highways provide rest stops for this purpose, and it is important to pull all the way off the highway to rest to avoid collisions.
Drivers should also ideally avoid driving at night, or travel with a companion who can share driving responsibilities. It is also important to rest before a major trip, and such expeditions should be started early in the morning, leaving the day clear for driving. Stretching and setting aside time for breaks during trips is also a great way to prevent fatigue. Many governments also recommend reducing driver fatigue by setting achievable distance goals, and recognizing the signs of sleepy driving early. It is better to pull over and be a bit late than get into an accident.
In the United States, the National Sleep Foundation estimates that around 20% of crashes may involve fatigued drivers. 37% of drivers in a 2003 National Highway Traffic Safety ministration admitted that they had fallen asleep while driving. The risk of traffic accidents goes up at night due to a variety of factors, but fatigue is a major issue, and this risk also increases in rural and remote areas. The National Sleep Foundation asks drivers to “Drive Alert, Arrive Alive®.”
