Driver fatigue - get the facts

Fatigue is one of the top five factors contributing to road crashes.

Fatigue doesn’t only relate to falling asleep at the wheel – even brief lapses in concentration can have serious consequences.

It’s believed fatigue played a part in the deaths of 28 people in road crashes in Queensland in 20151. However, the actual number may be much higher because it can be difficult know if fatigue contributed to a crash. Often it’s one of a number of factors.

The facts

  • Being awake for about 17 hours has a similar effect on performance as having a blood alcohol content of 0.052.
  • Fatigue-related crashes are often severe and frequently occur when the driver is alone.
  • Most sleep-related vehicle crashes happen between 2am and 6am, and between 2pm and 4pm3.
  • Of all drivers and riders involved in serious fatigue-related crashes, approximately 75% are men4.
  • Young drivers are more likely to be involved in a fatigue-related crash.

Everyone can be affected by fatigue

Factors that may increase fatigue include:

  • lack of sleep or poor sleep — the quality as well as the quantity of sleep is important; for example, if you suffer a medical condition that means you don’t sleep well (such as insomnia or sleep apnoea), your driving could be affected. Or if it is frequently interrupted by a new baby, or shift work, for example, that too can have an effect. And it’s not just the sleep you get the night before you drive that’s important – missing out on quality sleep time is equally dangerous
  • the amount of time spent driving — long hours behind the wheel driving will lead to physical and mental fatigue
  • driving when your body wants to sleep — you will experience natural dips in alertness associated with your body’s rhythm. For example, if you are driving in the early hours of the morning when you’d normally be sleeping
  • monotony - driving along stretches of straight road may lead to a loss of concentration
  • individual characteristics - our age, physical condition and use of alcohol also influence how fast we become tired and how well we cope with fatigue.

How does fatigue affect driving?

When you are fatigued your driving performance can be affected in many ways:

  • vigilance and alertness deteriorate
  • concentration suffers
  • performance is impaired
  • reaction times suffer
  • judgement is impaired.

Watch for the warning signs

It’s important to recognise the warning signs of fatigue. You should stop driving if you are:

  • drifting in the lane or over lane lines
  • changing speed without reason
  • yawning
  • blinking more than usual
  • notice your eyes closing for a moment or going out of focus
  • feeling drowsy, tired or exhausted
  • having trouble keeping your head up
  • don’t remember the previous few minutes of driving
  • experience slower reaction times
  • ‘microsleeping’.

Myth busters

‘Drinking coffee or other caffeinated drinks will keep me awake’

Sleep is the only way to relieve tiredness. Caffeine, fresh air and loud music won’t stop you from being tired. These temporary fixes can give false confidence, telling you that you’re okay to continue driving.

‘Fatigue is only an issue on long trips’

Any driver can suffer tiredness, even on short trips. Over 50% of fatigue-related crashes happen within 25km of the departure point5.

Tips to avoid driving fatigued

Before you drive, make sure you:
  • get a good night’s sleep
  • avoid driving at times you’re normally sleeping
  • avoid long drives after a day’s work
  • understand the effects any medicine you’re taking might affect your driving
  • plan to include regular rest breaks on long trips
  • know and look for the warning signs of fatigue
  • when possible, arrange to share the driving
  • when you know you’re fatigued, avoid driving altogether. Take a taxi, public transport or rely on another driver.
If you feel tired when driving, make sure you:
  • pull over in a safe place (such as a rest area or ‘driver reviver’ site) and take a break or even a nap
  • when possible, share the driving.

  1. Department of Transport and Main Roads QLD, unpublished. Data extracted 29 March 2016.
  2. Williamson, A. M. and Feyer, A. M. (2000). ‘Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication.’ Occupational and Environmental Medicine 57(10): 649-655.
  3. Horne, J. A. and Reyner, L.A. (1995) ‘Sleep related vehicle accidents.’ BMJ 310(6979): 565-567.
  4. Department of Transport and Main Roads QLD, unpublished. Data extracted 31 July 2015.
  5. Department of Transport and Main Roads QLD. (2015). ‘Analysis of the distance from origin of journey to crash location for fatigued drivers’ (Rqc20238), unpublished

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