Driving tired can be dangerous

The Dangers

Driver fatigue causes hundreds of road accidents each year. And these accidents are roughly 50% more likely1 to result in death or serious injury. When drivers fall asleep, they can’t brake or swerve, so accidents tend to be high-speed collisions.

We all know that we shouldn’t drive when we’re too tired, but sometimes weather, logistics, lack of alternatives or time constraints2 mean we do anyway. However, driving while fatigued or sleepy leads to impairment of driving performance by increasing reaction times and reducing attention, compromising decision-making and our ability to control the vehicle. It’s incredibly risky.


  1. ROSPA
  2. Armstrong, Obst, Banks & Smith, 2010; McCartt et al., 2000; Nordbakke & Sagberg, 2007

Accidents caused by tiredness are roughly 50% more likely to result in death or serious injury

Comparable to drink-driving

Driving whilst tired can impair driving skills in a way comparable to drink-driving. A person who drives after being awake for 17 hours has impaired driving skills comparable to a driver with a 0.05 mg/ml blood alcohol level. A driver who hasn’t slept for 24 hours has impaired driving skills comparable to a driver with an illegally high blood alcohol concentration of 0.1 g/l1.


  1. Williamson & Feyer, 2000

The Facts

  • 1 in 3 UK drivers (31%) admit having experienced a microsleep at the wheel1. A ‘microsleep’ occurs when someone nods off for between two and 30 seconds without realising or remembering it, often known as head-nodding. It usually happens when people are tired but trying to stay awake, most common in monotonous situations, like motorway driving at night.
  • Nearly two fifths of UK drivers (37%) say they have been so tired they have been scared they would fall asleep when driving.2
  • 49% of UK drivers admitted driving after less than five hours’ sleep, highlighting that many drivers continue to drive whilst tired.3
  • Men (17%) are three times as likely as women (5%) to say they have fallen asleep at the wheel.4
  • 18 to 30-year-old males are more likely to fall asleep at the wheel when driving late at night.5
  • Sleep apnoea is the most common sleep related medical disorder and it significantly increases the risk of traffic accidents.6
  • Research suggests that sleep-related vehicle accidents are under-reported and are likely to account for 16% to 20% of UK vehicle accidents and up to one quarter of fatal and serious accidents7.


  1. brake.org.u
  2. AA Driving tired can be fatal
  3. brake.org.u
  4. AA Driving tired can be fatal
  5. UK Government
  6. UK Government
  7. Anund, Kecklund, Vadeby, Hjälmdahl & Åkerstedt, 2008; Schwarz et al., 2012

Tackling Tiredness Myths

Drivers regularly use countermeasures to tackle their tiredness, such as stopping for a walk, opening a window or turning on the radio. But these don’t work . Whilst taking a quick break or drinking a caffeinated drink can make a short-term difference, it’s a temporary measure. The sleepiness will keep returning until you’re properly rested.

To find out how to properly address tiredness, check out our top tips to avoid falling asleep at the wheel below.


It’s easy to underestimate the risk of actually falling asleep behind the wheel. But it can be fatal. To minimise this risk, follow these tops tips:

  • Make sure you’re well rested and feeling fit and healthy (and not taking any medication that causes drowsiness).
  • Take breaks at appropriate intervals (20 minutes every 1-2 hours).
  • Don’t drive if you feel tired. Pull over, drink a coffee, and then take a nap while the caffeine kicks in.
  • Always remember to stop in a safe place.
  • Avoid driving when you’d normally be sleeping – between about midnight and 6am.
  • Also be extra careful when driving between 2pm and 4pm (especially after you’ve eaten a meal).
  • Be aware of long journeys on monotonous roads, like motorways.
  • Plan your journey
    • Allow sufficient time for journey and breaks.
    • Schedule an overnight stop if the total journey is over 12 hours.
    • Do not drive for more than 7.5 hours.
    • Plan to take the train or bus instead if you know you’re likely to be tired (e.g. you’ve finished a long shift, or you’ve been out the night before).
    • If you suffer from sleep apnoea with excessive sleepiness, you should not drive until your symptoms are under control.


  1. Sleep Apnoea Trust