Asleep at the wheel.

• Author: Essex, Amanda
• Position: TRENDS

Drowsy drivers were involved in less than 3 percent of fatal motor vehicle crashes between 2005 and 2009, according to official government statistics. But a new AAA report paints a very different picture. According to the automobile association, between 2009 and 2013, drowsy driving was a factor in 21 percent of fatal crashes and 13 percent of crashes involving hospitalizations.

It's very difficult to tell when a driver is sleepy, drowsy or fatigued. While alcohol- or drug-impaired driving leaves physical evidence, drowsy driving does not. Drivers involved in crashes may be hesitant to admit they were fatigued, unaware of how tired they were or even unaware that they dozed off at all.

The official government statistics come from the National Highway Traffic Safety Administration, which relies solely on police officers' reports following accident investigations. To track drowsy driving, AAA examines the police reports as well, but also uses trained investigators to interview drivers and passengers, and analyzes data from a large sample of crashes.

Drowsy driving is certainly a safety hazard: Drowsy drivers have slow reaction times, poor judgment, impaired vision, lowered attentiveness and a lack of alertness.

But drowsy driving is also a difficult issue to legislate, and only a few state legislatures have done so. In 2013, Arkansas made the offense of "fatigued driving" a negligent homicide (a class A misdemeanor) if the driver has not slept in 24 hours and causes a...