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Less Than 4 Hours of Sleep? 15 Times More Likely to Cause a Car Collision


Not getting enough shut-eye each night can be detrimental to your health. It can also affect your ability to drive, according to a new report.

Over the past several years, numerous studies and public health and safety campaigns have focused on reminding us just how dangerous driving while tired can be. Although fatigue and a lack of sleep have become part of daily life for many people, these efforts have shown us that drowsy driving, according to an older study from 2016, can be just as dangerous as driving drunk.

Researchers haven’t let up on studying the impact of fatigue when it comes to our driving abilities. In fact, new research suggests that sleep-deprived drivers may be an even bigger problem than previously thought.

Researchers from the AAA Foundation for Traffic Safety recently conducted a study, published in the Sleep journal, to determine the relationship between sleep deprivation and motor vehicle crashes.

“While the dangers of driving drowsy were already well known, this is the first peer-reviewed study to quantify the relationship between how much a driver has slept and his or her risk of being responsible for a crash,” the authors wrote.

For their assessment, they examined data from a previous trial administered by the United States Department of Transportation, which included information on 5,470 crashes, including interviews with the drivers involved.

After analyzing the results, they found an estimated 7 percent of all motor vehicle crashes in America and 16 percent of fatal crashes involve driver drowsiness.

Upon further investigation, they discovered drivers who got fewer than four hours of sleep were 15 times more likely to cause a car collision, compared to those who received seven to nine hours. In fact, they compared the risk to that of drivers with a blood alcohol concentration roughly 1.5 times the legal limit.

“Being awake isn’t the same as being alert. Falling asleep isn’t the only risk,” coauthor Brian Tefft said in a statement. “Even if they manage to stay awake, sleep-deprived drivers are still at increased risk of making mistakes—like failing to notice something important or misjudging a gap in traffic—which can have tragic consequences.”

The scientists also revealed drivers who slept less than four hours had an elevated risk of single-vehicle crashes, which are more likely to result in injury or death. Furthermore, those who had changed their sleep or work schedule in the past week and those who had been on the road for three hours or longer without taking a break also had an increased risk.

As we all know, sleep is a critical component to the way we function in our daily lives. For any number of reasons, though, most people tend to underestimate the dangers they pose to themselves and others when they get behind the wheel while deprived of sleep. To help ensure your safety and the safety of those around you, it’s important to prioritize sufficient and quality sleep, and take steps to avoid drowsy driving.