The AAA Foundation’s Acute Sleep Deprivation and Risk of Motor Vehicle Crash Involvement report found that in a 24-hour period, crash risk for sleep-deprived drivers increased steadily when compared to drivers who slept the recommended seven hours or more:
• Six to seven hours of sleep: 1.3 times the crash risk
• Five to six hours of sleep: 1.9 times the crash risk
• Four to five hours of sleep: 4.3 times the crash risk
• Less than four hours of sleep: 11.5 times the crash risk
AAA urges drivers to not rely on their bodies to provide warning signs of fatigue and should instead prioritize getting plenty of sleep (at least seven hours) in their daily schedules.
For longer trips, drivers should also:
• Travel at times when normally awake
• Schedule a break every two hours or every 100 miles
• Avoid heavy foods
• Travel with an alert passenger and take turns driving
• Avoid medications that cause drowsiness or other impairment
Who is at risk for drowsy driving?
Sleep related crashes are most common in young people, especially men, adults with children and shift workers. According to the National Sleep Foundation:
• Adults between 18-29 are much more likely to drive while drowsy compared to other age groups.
• Men are more likely than women to drive while drowsy (56 percent vs. 45 percent) and are almost twice as likely as women to fall asleep while driving (22 percent vs. 12 percent).
• Adults with children in the household are more likely to drive drowsy than those without children (59 percent vs. 45 percent).
• Shift workers are more likely than those who work a regular daytime schedule to drive to or from work drowsy at least a few days a month (36 percent vs. 25 percent).
• Sleep deprivation increases the risk of a sleep-related crash; the less people sleep, the greater the risk.
• According to a study by the AAA Foundation for Traffic Safety, people who sleep six to seven hours a night are twice as likely to be involved in such a crash as those sleeping eight hours or more, while people sleeping less than 5 hours increased their risk four to five times.
• A study by researchers in Australia showed that being awake for 18 hours produced an impairment equal to a blood alcohol concentration (BAC) of .05, and .10 after 24 hours; .08 is considered legally drunk.
Other research indicates commercial drivers and people with undiagnosed sleep disorders such as sleep apnea and acute insomnia are also at greater risk for fall asleep crashes.
• Nearly three-quarters of adults in America (71 percent) drive a car to and from work, and many are drowsy drivers, according to NSF’s 2001 Sleep in America poll. More than one-fourth of these respondents (27 percent) said they have driven drowsy to or from work at least a few days a month, 12 percent drove drowsy a few days a week, and four percent said they drove drowsy every day or almost every day.
Drowsiness and driving is a dangerous combination, comparable to drinking and driving. With the holidays upon us, people are aware of the hazards of being drunk behind the wheel, but may not realize that being sleepy can be fatal as well.
A recent Gallup poll states that 40 percent of the country gets less than the recommended amount of sleep each night, said Kathy Weaver, director of the Sleep Lab at Pawnee Valley Community Hospital in Larned. These missed hours of sleep account for 6,400 traffic related deaths each year this makes up 21 percent of the US total traffic related deaths.
“If you didn’t get a good night’s rest due to lack of quality or quantity, it could cause you to uncontrollably fall asleep or be less alert while driving, Weaver said. “It also could cause many other health risks like high blood pressure, type 2 diabetes, memory loss, depression, obesity, heart disease and so much more.”
“Like alcohol, sleepiness slows reaction time, decreases awareness, impairs judgment and increases your risk of crashing,” said Kristen Knutson, research fellow at the National Sleep Foundation. But, “it’s nearly impossible to determine with certainty the cause of a fatal crash where drowsy driving is suspected.”
According to the foundation, 60 percent of adult drivers – about 168 million people – say they have driven a vehicle while feeling drowsy in the past year, and more than one-third have actually fallen asleep at the wheel. In fact, of those who have nodded off, 13 percent say they have done so at least once a month.
Four percent – approximately 11 million drivers – admit they have had an accident or near accident because they dozed off or were too tired to drive.
The National Highway Traffic Safety Administration estimates 100,000 police-reported crashes are the direct result of driver fatigue each year. This results in an estimated 1,550 deaths, 71,000 injuries, and $12.5 billion in monetary losses.
“These figures may be the tip of the iceberg, since currently it is difficult to attribute crashes to sleepiness,” Knutson said.
Symptoms of drowsy driving can include having trouble keeping eyes open, drifting from lanes or not remembering the last few miles driven. However, more than half of drivers involved in fatigue-related crashes experienced no symptoms before falling asleep behind the wheel.
Why is it a problem?
“It is very important to get good quality sleep and quantity of sleep,” Weaver said. “Your body has an internal clock that tells you when it is time to be asleep and when it is time to be awake.”
This clock is located in the brain just above an area where the nerves travel to the eyes, she said. These also control body temperature, alertness and the daily cycle of many hormones.
The word “circadian” means to occur in a cycle of about 24 hours. “Circadian rhythms make you feel sleepy or alert at regular times every day. You become sleepy in the evening at bedtime. You also become sleepy again at mid-day.”
And, Weaver said, many Americans are more prone to being sleepy.
A recent study published in the Journal for Sleep found people with obstructive sleep apnea were 2.5 times more likely to be the driver in an accident than people without sleep apnea. “Fortunately, the study also showed that when diagnosed and treated those same people reduced the risk by 70 percent by using the device prescribed for at least four hour per night.”
Excessive daytime sleepiness is a common symptom of OSA and can increase your risk for driving accidents, Weaver said. “We have seen a large amount of patients here at Pawnee Valley Sleep Center that complain of dosing off at the wheel and most often undiagnosed with Obstructive Sleep Apnea.”
How much is not enough
Drivers who miss between one to two hours of the recommended seven hours of sleep in a 24-hour period nearly double their risk for a crash, according to new research from the AAA Foundation for Traffic Safety. The Centers for Disease Control and Prevention says that 35 percent of U.S. drivers sleep less than the recommended seven hours daily. And with drowsy driving involved in more than one in five fatal crashes on U.S. roadways each year, AAA warns drivers that getting less than seven hours of sleep may have deadly consequences.
“Drivers cannot miss sleep and still expect to be able to safely function behind the wheel,” said Jim Hanni, AAA spokesperson. “New research shows that a driver who has slept for less than five hours has a crash risk comparable to someone driving drunk.”
The AAA Foundation for Traffic Safety’s report, Acute Sleep Deprivation and Risk of Motor Vehicle Crash Involvement, reveals that drivers missing 2-3 hours of sleep in a 24-hour period more than quadrupled their risk of a crash compared to drivers getting the recommended seven hours of sleep. This is the same crash risk the National Highway Traffic Safety Administration associates with driving over the legal limit for alcohol.
While 97 percent of drivers told the AAA Foundation they view drowsy driving as a completely unacceptable behavior that is a serious threat to their safety, nearly one in three admit that at least once in the past month they drove when they were so tired they had a hard time keeping their eyes open.