What is Drowsy Driving?

Photo of a tired man behind the wheel of a vehicle

Drowsy driving occurs when a person operates a motor vehicle when too fatigued or sleepy to stay alert, making the driver less aware of their surroundings. Drowsy driving is a serious problem and causes a threat not only to the driver but to others on the road as well. The US Department of Transportation estimates that 100,000 accidents reported are due to drowsiness and/or fatigue. These crashes result in 1550 deaths annually (4% of traffic fatalities) and $12.5 billion in monetary losses. 

What is the difference between fatigue and drowsiness?

Fatigue is the deterioration in mental or physical performance due to prolonged physical or mental work - it occurs even in people who have had adequate sleep.  All that may be needed to recover from fatigue is a rest from this work, or a change in activity (a change is as good as a rest).  Sleep may not be needed if adequate sleep has already been taken. 

Drowsiness on the other hand is the likelihood of falling asleep, due to inadequate sleep, prolonged wakefulness, or working through the night. It is a cognitive impairment that typically refers to the time right before sleep occurs.  Since we cannot force our bodies to stay awake, this period in which we have no control over intermittent lack of awareness or microsleeps (often only for a few seconds) is characterized as excessive drowsiness, and unlike fatigue cannot be resolved with rest. When you are drowsy, you require sleep.

What is the difference between rest and sleep?

Rest and sleep are not the same. Rest is a break or even a simple change of activity from a fatiguing task, but you remain awake. Rest can restore energy, but it cannot substitute for sleep, nor can lack of sleep be corrected simply by resting. Sleep allows both body and brain to recuperate, to be restored and refreshed.

Signs of drowsy driving

  • Finding it difficult to concentrate, missing your exit
  • Difficulty remembering the last few miles driven
  • Frequently adjusting driving position 
  • Stretching, yawning and blinking frequently
  • Head nodding, fighting to keep eyes open
  • Drifting from lane to lane, hitting the rumble strip

Drowsy driving can lead to

  • Attention difficulties
  • Slower reaction times
  • Slower, muddled thinking    
  • Erratic speed control 
  • Sloppy steering

Drowsy driving can be as dangerous as driving under the influence

According to the CDC, studies have shown that going too long without sleep can impair your ability to drive the same way as drinking too much alcohol. “Being awake for at least 18 hours is the same as someone having a blood content (BAC) of 0.05%. Being awake for at least 24 hours is equal to having a blood alcohol content of 0.10%. This is higher than the legal limit (0.08% BAC) in all states.”

Myths about drowsiness:

Many drivers claim to have their own strategies for keeping awake/alert for longer on long or monotonous car journeys (from cold air to stretching to turning up the radio).  Researchers have tested these countermeasures to see if they work and they have been shown to have a very limited effect - at best there is only a brief period when you feel a little more alert, but as you approach the “biological brick wall” of falling asleep uncontrollably, they no longer help.  It is difficult to assess for yourself just how much sleep loss is affecting you, and how close you are to slipping uncontrollably into sleep. Research has shown that many of the drivers involved in sleep-related accidents did not recognize they were in need of sleep, and believed they were well-rested when they were not.

Who is responsible for managing driver tiredness?

Effectively managing driver tiredness is both the responsibility of the organization and the individual. The organization has a legal responsibility and a duty-of-care to provide drivers with a safe system of work that provides adequate time off for sleep and to attend to family and social responsibilities. Drivers have a legal responsibility to ensure that they use their time off to obtain sufficient sleep and attend work in a fit and rested state. 

In order to effectively tackle driver tiredness both the organization and drivers must fulfill their responsibilities. Nothing is achieved if drivers are provided with sufficient time off to get adequate sleep and they use this time to work another job or stay out late at night. Similarly, it doesn’t matter how diligent a driver is about getting enough sleep, if he/she is expected to work a schedule that provides insufficient time off, driver tiredness will inevitably be a problem.

How to improve drowsy driving in your fleets

  1. Educate your drivers: Driver training can assure that your drivers understand the differences between fatigue and drowsiness and the importance of getting enough sleep. Like food and water, we need sleep to survive.  On average we need about 7-8 hours sleep a night. Sleepiness (like hunger or thirst) is a signal from the brain that you are not meeting a vital biological need.  However sleepiness is different, because if you keep ignoring this message, eventually you will fall asleep, whether you want to or not. 
  2. Be proactive: Make sure your drivers plan their long trips ahead of time by plotting out the rest stops in advance, so they can manage their tiredness before it becomes dangerous.
  3. Use a real-time AI driver alert system: Helping your drivers stop driving drowsy is critical to road safety. Fleet managers do not have the time to ride along with every driver, but they can rely on a driver and fleet safety platform that detects drowsy driving the moment it occurs and coaches drivers to return their focus to the road or pull over and rest — all in real-time. 
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