The American Automobile Association put cameras in thousands of cars and followed drivers for months.
The cameras were focused on their faces. Some of those drivers got into accidents, and sure enough, the cameras recorded the drivers nodding off.
According to the AAA Foundation for Traffic Safety, the problem is about eight times higher than federal estimates indicate.
Researchers in the study found that 9.5 percent of all crashes and 10.8 percent of crashes resulting in significant property damage involved drowsiness. Federal estimates indicate drowsiness is a factor in only 1 to 2 percent of crashes.
It's clearly a big issue, but there are some simple things everybody can do to be a little safer. Knowing the warning signs of drowsiness can help drivers avoid dozing off behind the wheel.
The most common symptoms include:
- Having trouble keeping your eyes open
- Drifting from your lane
- Not remembering the last few miles driven
If you're experiencing those types of symptoms, it's recommended you pullover to a safe place and take at least a 20-minute nap -- no longer than 30 minutes is key to recharge yourself so that you can safely drive your vehicle again.
The most important thing: get enough sleep to begin with. AAA and other experts will tell you that drivers need at least seven hours of sleep per night.
AAA also recommends that drivers travel at times of the day when they are normally awake, avoid heavy foods and avoid medications that cause drowsiness or other impairment.
For longer trips, drivers should schedule a break every two hours or every 100 miles, and travel with an alert passenger and take turns driving.