New research released by the AAA Foundation for Traffic Safety shows that driving drowsy is just as risky as driving drunk, finding that the lesser the amount of sleep, the greater the risk of accident. “You cannot miss sleep and still expect to be able to safely function behind the wheel,” said David Yang, the executive director for the foundation. “Our new research shows that a driver who has slept for less than five hours has a crash risk comparable to someone driving drunk.”
Data from the National Motor Vehicle Crash Causation Survey was used to determine just how much driving ability decreases when sleep deprivation increases. Getting even just one hour less than the recommended seven hours of nightly sleep can increase your risk of accident. Drivers who slept for less than 4 of the last 24 hours had an 11.5 percent higher risk of getting in a crash. Drivers who slept 4-5 hours had a 4.3 percent higher risk. And those who slept 6-7 hours had a 1.3 percent higher risk. These percentages could be even greater, as data from crashes occurring between the hours of midnight and 6:00 am was not available, and other studies have shown that the effects of sleep deprivation are greatest during the early morning hours.