Asleep at the Wheel: The Prevalence and Impact of Drowsy Driving

Background Most past studies of crash data estimate roughly 1% - 4% of crashes involve a drowsy driver BUT Many researchers believe that official statistics underestimate the prevalence of drowsy driving AND A few studies using different data and methods have suggested that the prevalence of drowsy driving may be much higher

The Study Available online at Published November 8, 2010

Part I: Prevalence of Drowsy Driving among Drivers

Method Data collected as part of the AAA Foundation’s 2010 Traffic Safety Culture Index Nationally-representative telephone survey of 2,000 U.S. residents 16 and older, conducted May 11 – June 7, 2010 Asked respondents about experiences with falling asleep at the wheel and general drowsy driving

Key Findings 41% reported having “fallen asleep or nodded off” while driving at least once in their lifetime 11% in past year 4% in past month 27% said they had driven while they were “so sleepy that [they] had a hard time keeping [their] eyes open” in the past month

Additional Findings Men much more likely than women (52% vs. 30%) to report having fallen asleep while driving Only 21% reported they had been driving for three hours or more when they fell asleep at the wheel; 59% said they had been driving for less than an hour before falling asleep; Only 28% said they felt sleepy when they started driving; 71% said they felt awake enough to drive

Part II: Proportion of Crashes Involving a Drowsy Driver

Method Analyzed data from nationally-representative sample of crashes in which a car, light truck, van, or SUV was towed Years 1999 – 2008 Sample included 80,821 vehicles involved in 47,597 crashes Drowsiness = unknown in 45% of cases  used statistical technique of multiple imputation to estimate proportion that were drowsy

% of Crashes that Involved a Drowsy Driver Data: Representative sample of 47,597 crashes in which a passenger vehicle was towed, 1999 – (National Automotive Sampling System Crashworthiness Data System, compiled by National Highway Traffic Safety Administration) Missing values of drowsiness imputed 10 times and averaged.

Additional Findings Drivers years old nearly twice as likely to be involved in a drowsy driving crash as drivers ages 40+ Two out of three drivers involved in a drowsy driving crash were men Drivers travelling alone nearly 2x as likely to be in drowsy driving crash compared to drivers with passengers 57% of drowsy driving crashes were single vehicle crashes where driver drifted out of lane or off road

Tips for Avoiding Drowsy Driving Get at least 6 hours of sleep the night before a long trip (preferably 8; no less than 6) Travel at times you are normally awake; stay overnight en route instead of trying to drive straight through Schedule a break every 2 hours or 100 miles Don’t work all day and drive all night Travel with a passenger who is awake Drink a caffeinated beverage, but remember that it takes 30 minutes for effects to kick in

For more information, go to: AAAFoundation.org

The AAA Foundation for Traffic Safety is a 501(c)(3) public charity located in Washington, DC that is dedicated to saving lives and reducing injuries. It is supported by donations from AAA/CAA Clubs, AAA/CAA members, and other organizations associated with AAA/CAA.