Drivers who only sleep four to five hours a day are twice likely to end up in accidents than those who got seven or more hours of sleep, reports a recent study.

Accident Risk Increase With Sleep Deprivation

It is noted that the rate of crash increases with decrease in sleeping hours of the driver. In other words, the diver who has had less than five hours of sleep had four times increased risk of accident much similar to drunk driving.

Jake Nelson, director of Traffic Safety Advocacy & Research for AAA Foundation for Traffic Safety noted that it is not advisable to drive a vehicle if the person hasn't got seven hours of sleep in the past 24 hours.

Study On Association Between Sleep And Accident

Earlier studies have reported that about 20 percent of the accidents in the United States were caused by sleep-deprived drivers. Meanwhile, the National Highway Traffic Safety Administration has reported that about 35,092 fatalities in road crash were recorded in 2015, which account to 7.2 percent increase in rate when compared to 2014.

Nelson also noted that in recent days it is becoming very tough to maintain a balance between work and life, and in most cases people sacrifice sleep to bridge the gap. People who don't get healthy amount of sleep are risking not only their own lives but also others' on the road.

The current study by AAA considered NHTSA's National Motor Vehicle Crash Causation Survey that examined 4,571 crashes between July 2005 and December 2007. The accidents included in the study were those that took place between 6 a.m. and 11:59 p.m.

Number of hours of sleep the drivers got in the past 24 hours of the day before the accident was recorded. They were also asked if they had any naps longer than half an hour or more that particular day. With both the data, the researchers calculated the total number of hours of sleep the drivers had the whole day.

Crash Risk Increases With Every Hour Of Sleep Loss

While more drivers involved in the accidents were found to have had seven hours of sleep in the past 24 hours it was less likely that they contributed to the crash. The majority of drivers contributed to the crash were found to have had less than four hours of sleep or so.

The chances of crashing increased with decrease in sleeping hours. There is 1.3 times increased risk of accidents when a person had six to seven hours of sleep and 1.9, 4.5 and 11.5 times increased risk were observed when the driver had five to six, four to five and less than four hours of sleep respectively.

"You cannot miss sleep and still expect to be able to safely function behind the wheel," said David Yang, executive director for the AAA Foundation for Traffic Safety.