PITTSBURGH — Something that most drivers experience but may not realize until it’s too late – feeling drowsy – plays an undetermined role in traffic crashes, injuries, and deaths.
Although underreported in government statistics, previous research by the AAA Foundation for Traffic Safety has estimated that 16% to 21% of all police-reported fatal vehicle crashes likely involve drowsy driving. And new Foundation research finds that drivers may underestimate their drowsiness, leading them to stay behind the wheel rather than stopping for a much-needed break.
“Motorists need to understand the dangers of drowsy driving and that it is a condition that does not resolve or improve with continued driving,” said Terri Rae Anthony, safety advisor, AAA East Central. “Our goal is to help drivers learn to pay serious attention to the early warning signs of drowsiness so they can stop, rest and then continue their journey as safely as possible.”
Drowsiness refers to a state of increased tendency to fall asleep. Beyond the danger of falling asleep at the wheel, drowsiness also impairs drivers by reducing their alertness. Crashes caused by drowsy driving tend to be severe because the driver may not attempt to brake or swerve to avoid a collision, so the resulting impact occurs at a high rate of speed. A drowsy driver may also be startled and lose control of the vehicle.
Researchers designed a 150-mile simulated nighttime highway driving experiment for the study. Every 20 miles, there was a simulated “rest area” at which participants could stop, leave the driving simulator, walk around, nap, drink coffee or eat a snack. A monetary incentive encouraged drivers to complete the drive as quickly as possible while incentivizing them to avoid crashing. Researchers used a brief survey to gauge how drowsy drivers felt and measured the percentage of time their eyes were closed to gauge sleepiness.
Levels of drowsiness generally increased throughout the simulated highway driving experiment. Participants were usually aware that they were drowsy, but their perceptions of the extent of their sleepiness were not always accurate and affected decision-making.
The results demonstrate a need to help drivers recognize how drowsy they are. Knowing the warning signs of drowsiness can help drivers avoid dozing off behind the wheel. The most common symptoms include:
