Research Update: Drivers Commonly Underestimate Their Level of Drowsiness Behind the Wheel

In its latest study, the AAA Foundation for Traffic Safety examined how drivers perceive their own drowsiness.  Using a simulator, participants were asked to drive a long distance trip, and were given the opportunity to take a break every 20 minutes.  How did they do?  The results don’t look good:

  • During the three-hour simulated drive, half the participants chose to take no break at all, despite the recommendation to take a break every two hours or every 100 miles.
  • When drivers reported “low” perceived levels of drowsiness, the objective measure suggested that 75% of them were moderately or highly drowsy.
  • Participants rated their drowsiness as low on 25% of occasions when the objective measure indicated high drowsiness (eyes closed for more than ¼ of the time over a one-minute interval.)

It’s clear that there is opportunity to help educate people about how to be more accurate and conservative regarding their perceptions of how tired they are while driving, and driver education can play a key role in that effort.

See the two-page Fact Sheet and the full Technical Report at: