What can you do to prepare for safe holiday road trips this year? Try getting the recommended seven to eight hours of sleep each night.
Drivers who are just one or two hours shy of that recommendation nearly double their risk for a crash the next day, according to a new study conducted by the AAA Foundation for Traffic Safety (PDF) and released Tuesday.
“While we do not think anybody would be surprised to learn that driving while extremely sleep-deprived increases a driver’s risk of being involved in a crash — this admittedly is rather intuitive — we were surprised to find a detectable increase in crash risk when a driver had slept even just one hour less than the seven hours recommended by sleep experts,” said Brian Tefft, senior research association for the foundation, who led the new study.
A report published by the Centers for Disease Control and Prevention in February found that more than a third of adults in the United States reported getting less than seven hours of sleep daily.
The CDC even has called insufficient sleep a “public health problem.”
The new AAA study featured data on 7,234 drivers who were involved in 4,571 vehicle crashes, from 6 a.m. to midnight, between 2005 and 2007.
The data were from the National Highway Traffic Safety Administration’s National Motor Vehicle Crash Causation Survey, which included how much sleep drivers reported having in the 24 hours preceding a crash.
After analyzing the data, the researchers found that drivers who had slept for less than four hours had 11Â½ times the crash risk rate of drivers who had slept seven hours or more; drivers who had four to five hours of sleep had 4.3 times the risk; those who had five to six hours had 1.9 times the risk; and those who had six to seven hours had 1.3 times the risk.
In other words, “the crash risk of a driver who has slept for only four to five of the past 24 hours is approximately quadruple the risk of a driver who has slept for the expert-recommended minimum of seven hours, similar to the crash risk of a driver who is legally intoxicated relative to a sober driver,” Tefft said.