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Drowsy Driving? An Accident Waiting to Happen

Dec 14, 2020 5:01:28 PM / by DEKRA

After attending a workshop taught by DEKRA’s VP and expert on Brain-Centric Reliability, David Musgrave, I learned that a microsleep episode is a common occurrence when a person does not get enough restful sleep and their brain shuts down momentarily in attempt to recharge itself. Fatigue (including Microsleeps) is one of 12 precursors to human error and many times, serious injury and fatality. A Microsleep caused my best friend to crash her car into a truck. 

A Microsleep is defined as an uncontrollable, brief episode of sleep lasting anywhere from a single fraction of a second up to 10-15 seconds.  You’re exhausted and despite your best efforts to stay awake, your brain shuts off with your eyes still open. That’s what happened in the case of my friend.  The driver of the truck she collided with said, “I can’t believe you kept coming!  I was blowing my horn and you were looking right at me, but it was if you didn’t see me!” 

During a microsleep episode, your brain doesn’t respond to noise or other sensory inputs, therefore you won’t react in time to prevent an incident.  My friend wasn’t on the phone, she wasn’t distracted, but her brain had dropped momentarily into deep/Delta wave asleep!  With less than five hours of sleep for several nights in a row, her brain was taking a much-needed nap as she sat behind the wheel of a car. Talk about a wake-up call!

Listening to my friend recount the incident, my mind immediately flashed back to a video in David’s workshop showing a public transportation driver plowing into a car ahead of the driver on an interstate with eyes wide open. The video was intended to “drive” home the fact that sleep is a basic biological necessity, and when we force ourselves to go without it for too long, the brain will eventually shut down —even if just for a few seconds.

Unfortunately, you can’t control when or where it happens. In four or five seconds, traveling 55 miles per hour, you can travel more than 100 yards (the length of a football field) while asleep.

Drowsy driving, a related occurrence, contributes to more crashes than the federal government had initially estimated, according to a new study by the AAA Foundation for Traffic Safety2. The report released in February 2018 analyzed dash-cam video from more than 700 crashes and linked nearly 1 in 10 to drowsiness. Federal estimates indicate drowsiness is a factor in about 1 to 2 percent of crashes.

Sleepiness can result in crashes at any time of the day or night, but three factors are most commonly associated with drowsy-driving crashes.
  • They occur most frequently between midnight and 6 a.m., or in the late afternoon.
  • They often involve a single driver running off the road at a high rate of speed with no evidence of braking.
  • They frequently occur on rural roads and highways.
Error risk with less-than-adequate Sleep

Research shows the relative error risk is 240% greater with 5 ½ -6 hours of sleep and 490% greater with less than 5 ½ hours of sleep averaged over 7 days3. Not only does lack of sleep affect driving, but it also affects work safety. Imagine the injury possibilities if a worker had a microsleep episode at height or using a power tool.

So, what can you do to prevent a microsleep episode?

Driving Alert Means…
  1. Getting adequate sleep (7-9 hours for an adult, and 8-10 hours for teens4) daily is the only true way to protect yourself against the risks of driving when you’re drowsy. 
  2. Getting a good night’s sleep before the start of a long road trip.
  3. Avoiding even the smallest amounts of alcohol consumption before driving. Consumption of any alcohol interacts with sleepiness to increase drowsiness and impairment.
  4. Checking your prescription and over-the-counter medication labels to see if drowsiness could result from their use.
  5. Avoiding driving during the peak sleepiness periods (midnight – 6 a.m. and late afternoon). If you must drive, stay vigilant for signs of drowsiness, such as crossing over roadway lines or hitting a rumble strip.
Warning Signs of Microsleep
Consider the following warning signs of a potential microsleep episode:
  • You feel sleepy and have trouble keeping your eyes open;
  • You have difficulty focusing on where you are going or what you are doing;
  • You yawn a lot, and
  • Your thoughts wander.
If you notice the warning signs of microsleep while driving, pull over and rest for a few minutes. If at work, speak to your supervisor to plan work activities with lower exposure given your cognitive fatigue state. Take advantage of your company’s fatigue risk mitigation policy and procedures including individual fatigue assessment to determine your level of impairment. Lastly, listen to your body and get adequate sleep before beginning the next day’s activities – your brain will thank you as will other drivers on the road and colleagues at work!

Topics: Serious Injury and Fatality, safety, organizational safety, DEKRA, workplace injuries, Crisis, Workplace safety, Driver Safety, Road Safety


Written by DEKRA

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