WASHINGTON, D.C. — New research found that the percentage of crashes involving drowsiness is nearly eight times higher than federal estimates indicate, according to the AAA Foundation for Traffic Safety.

In releasing the research last month, the AAA Foundation for Traffic Safety said that because drowsiness is difficult to detect after a crash, drowsy driving is “one of the most underreported traffic safety issues.” To address that challenge, the new study analyzed dashcam video footage of drivers from more than 700 crashes.

Researchers examined video of drivers’ faces in the three minutes leading up to a crash. Using a scientific measure linking the percentage of time a person’s eyes are closed to their level of drowsiness, the researchers determined that 9.5% of all crashes and 10.8% of crashes resulting in significant property damage involved drowsiness. Federal estimates indicate that drowsiness is a factor in only 1% to 2% of crashes.

“Drowsy driving is a bigger traffic safety issue than federal estimates show,” said Dr. David Yang, executive director of the AAA Foundation for Traffic Safety. “Drivers who don’t get enough sleep are putting everyone on the road at risk. By conducting an in-depth analysis using video of everyday drivers, we can now better assess if a driver was fatigued in the moments leading up to a crash.”

Previous research released by the AAA Foundation for Traffic Safety in December 2016 showed that drivers who miss one to two hours of the recommended seven hours of sleep in a 24-hour period nearly double their risk for a crash.

The foundation’s new research brief, “Prevalence of Drowsy Driving Crashes: Estimates from a Large-Scale Naturalistic Driving Study,” is available here.