The Danger of Drowsy Driving

‘Driving with your eyes closed can kill you,’ expert says…

The crusade against drunk driving has gained a great deal of momentum, and rightly so. More than 15,000 people were killed last year in alcohol-related accidents, and the push to end this carnage is making historic progress. But as we make inroads against drunk drivers, there is another killer on the highways that gets far less attention. It’s more insidious than driving under the influence because it is harder to detect. And it is harder to stamp out because there are few laws that legislate against it. But it is a sure and certain killer, and in these days when many of us are working more days and longer hours, it seems destined to increase rather than decrease.

What is it?

Simple drowsiness. Driving while over-tired. Falling asleep at the wheel.

There is nothing new about this menace, but, after looking at the damage it has caused thousands of human lives each year, there is no doubt it is a problem with which we must deal. According to the National Highway Traffic Safety Administration, drowsiness is the primary causal factor in 100,000 police-reported crashes each year, crashes that resulted in 76,000 injuries and 1,500 deaths. While that seems like a significant menace, the NHTSA figures might well underestimate the extent of the problem. The NHTSA estimates mean that drowsy driving represents one to three percent of all police-reported crashes and four percent of fatalities, but other experts suggest the problem might be even bigger. A United Kingdom study concluded that as many as 20 percent of police-reported crashes were sleep-related, and an Australian study pegged the figure at six percent. In addition, NHTSA says that driver inattention was the primary cause of some one million accidents last year, and contributors to inattention are sleepiness and fatigue, which is exacerbated by sleep deprivation.

The fact that we, as a nation, are not getting enough sleep has been documented by many sources recently. In the 1998 Omnibus Sleep in America Poll, conducted by the National Sleep Foundation, some 32 percent of American adults said they sleep six or fewer hours per night, and 64 percent say they sleep less than the recommended eight hours. More than one-third of respondents told the survey they had experienced daytime drowsiness severe enough to interfere with their jobs. But what was most alarming was the fact that 57 percent of Americans said they had driven while drowsy in the past year and nearly one-quarter (23 percent) said they had actually fallen asleep at the wheel.

These statistics become truly scary when one examines them in light of a recent study conducted by the AAA Foundation for Traffic Safety and the University of North Carolina Highway Safety Research Center (HSRC). In the first-ever study of its kind, researchers, led by Dr. Jane C. Stutts, Dr. Jean W. Wilkins and Dr. Bradley V. Vaughn, studied hundreds of sleep and fatigue-related car crashes to identify the driver behavior that caused or contributed to them.

“Previous studies about drowsiness and driving were done in a laboratory,” said David K. Willis, president of the AAA Foundation for Traffic Safety. “This is the first time anyone has looked at real-world crashes to see what happens. And what happens is that drivers who have had six or less hours of sleep or who often drive between midnight and 6 a.m. put themselves at very high risk.”

The researchers used police crash reports and driver records to identify and interview 1,400 drivers. Included in the sample were four separate groups: drivers who crashed after falling asleep, drivers who crashed while fatigued, drivers who crashed for non-sleep reasons, and a control group of drivers who had not had a crash in three years. Each respondent was asked to complete a detailed questionnaire about work schedules, sleep habits, quality of sleep, amount of driving, and the circumstances surrounding each crash. Drivers were also asked questions to assess their present levels of sleepiness.

When the data was analyzed, large differences were found among the groups. One telling factor was that both those who crashed after falling asleep at the wheel and those who crashed while fatigued had slept substantially less than the drivers who crashed in non-sleep-related accidents and drivers in the control group, who had not crashed at all. Just a fifth of drivers involved in sleep- or fatigue-related crashes reported getting eight or more hours of sleep before the crash, compared with nearly half of the drivers in the control (non-crash) group.

The old Edgar Bergen line was, “They say hard work won’t kill you, but why take the chance?” Though said in jest, that advice seems quite apropos in light of the study’s findings. Not only was simple lack of sleep a significant factor in the sleep- and fatigue-related crashes, work schedules were also an important factor.

Compared to drivers in non-sleep-related crashes, drivers in sleep crashes were nearly twice as likely to work at more than one job, and their primary job was more likely to involve an atypical schedule. Some 14 percent of employed drivers involved in sleep crashes and 24 percent of employed drivers in fatigue crashes worked the night shift, and the study estimated that working a night shift increased the odds of a sleep-related crash by nearly six times. For those of you who regularly burn the midnight oil, you should know that working more than 60 hours a week increased the odds of having a sleep-related crash by 40 percent.

Drowsy driving is a difficult problem to confront, because many people who wouldn’t think of getting behind the wheel after a few drinks have no qualms about slipping into the driver’s seat when dog-tired. Unlike drinking and driving, there is little of no social stigma about driving while drowsy, and people who put in long working hours are universally lauded in our society.

If you, like many, feel that you’ll know when you’re too tired to drive, the study had this sobering finding: Around half the drivers in sleep-related crashes said they did not feel even moderately drowsy before they crashed, including many of those who were labeled by police reports “asleep at the wheel.” Many drivers simply do not know how sleepy they are.

The study indicated that “People need to think about sleep even when they don’t feel tired,” Willis said. “Driving with your eyes closed can kill you.”

Now that you know about the problem, here are some danger factors strongly associated with having a drowsy driving crash:

  • Sleeping less than six hours per night
  • Being awake for 20 hours or longer
  • Working more than one job and/or working night shifts
  • Frequent driving between midnight and 6 a.m.

The study also determined that drivers in sleep and fatigue crashes were more likely to try to deal with their drowsiness once they were on the road rather than by planning ahead and taking precautions such as getting enough sleep or using caffeine. Their stop-gap measures usually did little or no good.

It is the consensus of experts that the only truly effective strategy you can take to prevent a crash when you’re drowsy or fatigued is to stop driving immediately and get some sleep. Sadly, many drivers feel that is impossible for one reason or another, so they don’t make the effort to get proper sleep. In those instances, the authors of the study encourage drivers to stop, drink some caffeinated beverages (the equivalent of two cups of coffee) and take a brief nap before getting behind the wheel.

Perhaps the most important factor is to recognize that your drowsiness or fatigue can kill you and others. Hard work is praiseworthy, but not at the expense of lives.

About Tom Ripley 52 Articles
Born in Boston, Tom Ripley has been writing about the automotive industry and the human condition for more than a decade. He's a frequent traveller but nominally resides in Villeperce, France.