Nope – not texting or distracted driving. Day or night, the leading cause of auto accidents is...driving while tired, according to a study conducted by the Virginia Tech Transportation Institute.

The 100-car naturalistic driving study has shown that fatigue is a cause of 20 percent of crashes, rather than the 2 or 3 percent previously estimated based on surveys, simulator studies, and test tracks. And 18- to 20-year-olds account for significantly more fatigue-related crashes than any other age group. Adolescents’ sleep patterns shift to later hours; however, the school day still tends to start early, resulting in daytime sleepiness. Older drivers can face similar issues with late nights and early work times, but have more experience coping with moderate fatigue – although, not always.

“One of the most important results from the 100-car naturalistic driving study was the degree to which fatigue is a cause of accidents,” said Charlie Klauer, group leader for teen risk and injury prevention at the transportation institute’s Center for Vulnerable Road User Safety.

“A finding that surprised people is the prevalence of fatigue during the day. We found significantly more crashes/near crashes due to fatigue during the day than at night,” she said.

“The study allowed us, for the first time, to observe driver behavior just prior to a crash. In 20 percent of all crashes and 16 percent of all near crashes, the driver was showing fatigue. We saw eye-lid closure, head bobbing, severe loss of facial musculature, micro sleep – which is when your eyes drift shut and then pop up,” said Klauer. “This was not just yawning. The drivers were asleep.”

So, get more sleep! Have another cup of coffee or an energy drink before you drive to school or work. It could save your life! 

Source: Virginia Tech Transportation Institute, News Post – April 15, 2013, “Day or night, driving while tired a leading cause of accidents”