Drivers who fail to get at least seven hours a sleep per night face a much higher risk of being involved in an auto accident, and are also more likely to be the responsible party in a crash, according to the findings of new research.
In a study published last month in the medical journal Sleep, researchers found an elevated risk of culpable crash involvement for those who have slept less than seven hours in a 24 hour period, and even greater risk as the hours of sleep decreased, highlighting the dangers of drowsy driving.
Researchers examined data collected by the U.S. Department of Transportation on nearly 7,000 crashes, and driver interviews from 2005 to 2007, in an attempt to quantify a relationship between acute sleep deprivation and being responsible for a motor vehicle crash.
The study found that an increased risk of auto accidents when viewing the previous 24 hour sleep patterns of those involved in accidents. Researchers found those who got six, five, or four hours of sleep had 1.3, 1.9 and 2.9 times the odds of being the culpable party involved in a vehicle crash, when compared to those who received seven to nine hours of sleep.
Individuals who reported receiving less than four hours of sleep in the previous 24 hours, the data suggested they were 15.1 times more likely to be culpable for a crash, and 3.4 times more likely to be involved in a single-vehicle crash.
Drivers who were found to have recent sleep pattern changes and driving for more than three hours at a time were also found to have increased culpability rates.
Previous data has found millions of drivers in the U.S. fall asleep behind the wheel each month, with more than 15 percent of all fatal crashes involving drowsy drivers. Drowsiness causes a person to have slower reaction times and experience impaired attention, impaired mental processing, judgment and decision making.
Earlier this year in February, the AAA Foundation for Traffic Safety released a drowsy driving study that observed driving behavior of more than 3,500 drivers over a several month period as part of the federally funded Second Strategic Highway Research Program Naturalistic Driving Study. The study was conducted to determine the rate of drowsy driving on U.S. roadways.
Researchers observed 905 severe, moderate, and minor crashes and another 628 crashes that were classified as low risk not requiring the need of emergency responders. Approximately 8.8 to 9.5 percent of crashes observed involved a drowsy driver and between 10.6 and 10.8 percent of moderate crashes involved a drowsy driver.
Previous research by the U.S. National Highway Traffic Safety Administration (NHTSA) estimated drowsy driving to be responsible for approximately 6,000 fatalities annually. A 2017 report examined crash data from 2010, focusing on nearly 33,000 fatal crashes and nearly 4 million auto accidents resulting in injuries. The findings indicated drowsy driving accounted for 5,445 of the fatal crashes and more than 500,000 of the non-fatal collisions involving injuries.