Home » Blogs » Microsleep: the risk of drowsiness while driving

Microsleep: the risk of drowsiness while driving

21 August 2017

Drivers falling asleep at the wheel is a leading cause of fatal road traffic collisions. We look more closely at microsleep, what dangers it entails and how to prevent it.



What is Microsleep?

Microsleep is a short burst of sleep, that can be experienced by anyone. It can even occur without the person being aware that it happened. During a microsleep a person can lose attention and fall asleep. This can be just for a few seconds or even up to half a minute.


When does it happen?

Microsleep usually occurs when a person is tired or doing monotonous work, such a driving on a motorway. It usually happens during the times that our biological clock wants us to rest, such as at night and mid-afternoon.


How does it work?

Scientists are still unsure what happens in our brains during microsleep. However, some studies have shown that parts of the brain fall asleep, while others stay awake. Therefore, when we are tired our brain wants to sleep, so it starts to shut down, which causes microsleep.

Microsleep: the risk of drowsiness while driving

Why is it so dangerous?

Microsleep causes on-job-errors, and especially road collisions. According to to the AAA Foundation, 16.5 per cent of fatal crashes are due to drowsy driving, while it is known that 40 per cent of crashes involve commercial vehicles.

Drowsiness reduces the driver’s reaction time and awareness of the situation around them. It has even been proven that drowsy driving is more dangerous than drink driving.

If you are driving at 70 mph and you fall asleep for 6 seconds, that is 200 meters that you are not aware of. This is enough time to change lanes, go to the other side of the road, or pass through a traffic light.


Who is most likely to be affected by it?

People who are most likely to be affected by this are those working night shifts because they are working during the times when our bodies are programmed to sleep.

Medical conditions can also affect this, such as insomnia, sleep apnea, or sleep deprivation.

Feeling drowsy while driving is extremely dangerous! You should pull up and have a short nap

What are the signs of microsleep?

  • Feeling drowsy or sleepy
  • Finding it hard to keep your eyes open, tired or sore eyes
  • Heavy eyelids, slowly closing your eyes
  • Blank expression with an empty stare
  • Constant blinking
  • Restlessness
  • Difficulty focusing on the task, such as knowing where you are going
  • Constant yawning
  • Not concentrating on the task, thoughts starting to wander
  • Feeling moody or temperamental
  • Drifting on the road, not keeping in lane without realising it
  • Head jolting you awake
  • Slow reactions
  • Boredom

How to prevent it?

Fleet managers need to be aware of the dangers of microsleep and make sure their drivers have the right training and driving schedules to prevent mistakes from occurring.

  • Sleep well - make sure your drivers get adequate sleep before a long journey. An average adult needs 7 to 7.5 hours of sleep each night! It is crucial that drivers are well rested before they set off.
  • Get some rest - train drivers to recognise the signs of microsleep and encourage them to rest. Stopping the job to rest is much more safe and efficient.
  • Take regular breaks - include regular breaks in your driving plan so that drivers can take a power nap if they feel sleepy.
  • Schedule sensibly - if you do not have to, avoid driving during night times or afternoon dips. These are the hours when we feel most tired.
  • Have a second driver - for longer journeys it could help to have at least one more driver in the vehicle to swap every few hours.
  • Keep your focus - encourage drivers to listen to something that would keep them engaged, such as upbeat music. There are also apps to help drivers stay awake by vibrating and making noise. Make sure that they do not get distracted while driving and do not use mobile phones while on the road!
  • Eat healthy - encourage your drivers to eat healthy, foods containing carbohydrates and protein help to gain energy and stimulate the brain.
  • Have caffeine - this is effective for a few hours, but not long term. Make sure your drivers are aware that caffeine can make it harder to get to sleep in the evening, causing long term problems.
  • Have vitamins -  vitamin B and C boost energy!
  • Chew gum - not the healthiest option but it keeps the mouth moving and your mind alert.
  • Be aware of medication - if your drivers are taking any sort of medication, you need to know and make sure that you are aware of it’s side effects. Especially when they are starting a new drug, make sure that it does not have a drowsiness side effect. If it does, consider if it it safe for your drivers to drive! Even hayfever medication can make you sleepy!

The EASST Academy online course for Fleet Managers covers issues related to microsleep and what you can do to make sure your drivers stay safe and alert on the roads. Go to the course.

Sign up to our newsletter for more articles like this delivered straight to your inbox.

* indicates required


Find out more about microsleep: