The importance of sleep: the dangers of driver fatigue

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It is estimated that 20-30% of all fatal crashes on Australian roads are due to fatiguei. We take a look at the potential risks of driving when tired, the fatigue signs you should be aware of, and what to do if you experience them.

Driver fatigue is most commonly experienced during trips when the driver is sleep-deprived or during hours of normal sleep. In fact, you are four times more likely to have a fatal crash driving between 10pm and dawnii. Risk is also increased if the driver has taken medicine or is aloneiii. Notably, almost 30% of fatigue-related car deaths occur during holiday periodsiv, when people are driving late to make commitments or heading home from social occasionsv.

Driving at night when you are already drowsy can be very risky. Always take regular breaks to ensure you arrive home safely.

Country roads also present a higher risk of fatigue-related crashes; for example, the chance of getting involved in a fatal crash on a rural road in Queensland is 13.5 times more likely than on one of the State's urban roadsvi.

At-risk drivers

One of the most obvious at-risk drivers is someone who hasn't slept in a while. Due to the longer average trip lengths and lack of awareness of fatigue due to higher, monotonous speeds, rural drivers (and their passengers) are more at risk.

How fatigue affects driving ability

Fatigue affects most people in a similar way. It can impair performance and judgement, reduce attention, and cause slower reaction times. The result is poorer performance while doing the skilled task of driving, followed by an increased probability of falling asleep behind the wheelv.

Microsleeps can be particularly dangerous as your vehicle's stopping distance increases significantly due to the dramatic increase in your reaction times caused by fatigueiii.

The Transport Accident Commission of Victoria has compared impairment associated with driving while tired to driving while drunkvii. A driver who has been awake for 17 hours has the ability similar to a driver with blood alcohol concentration (BAC) of 0.05. For someone who's been awake for 24 hours, it is akin to having a BAC of 0.1vii.

Preventing a fatigue-related crash

Traffic authorities across Australia have pursued a number of advertising campaigns to address driver fatigue, with each approach synonymous with the message "Stop, Revive, Survive".

Signs of fatigue includev:

Anticipating fatigue and being aware of the signs can help you prevent a fatal or serious crash on the roadv. If you recognise the signs, you should take a break from driving, either by stopping completely in a safe location off the road or by changing driversviii.

Drowsiness, head nodding and microsleeps are all signs of fatigue that increase your chance of having a fatal car accident. Frequent breaks can help.

To do this, take frequent breaks when driving, especially during high-risk times (10pm to dawn), with every 2 hours being the recommended frequency of breaksiii. Also, try not to drive more than 8 to 10 hours every day. If possible, share the driving burden with passengers - especially for long trips.

Technological innovations

It is evident that driver fatigue is a significant problem. In response to this, some car manufacturers are devising new features that they hope will prevent fatigue-related crashes from occurring. For example, Mercedes-Benz has developed 'Attention Assist', which helps drivers detect their level of drowsinessix. It warns the driver of their level of fatigue and how much time has passed since their last break from drivingix. While it is hoped that such technology will reduce the number of crashes caused by fatigue, ultimately, it is your responsibility as a driver to respond to your level of drowsiness and take appropriate breaks from driving when necessary.

i Australian Transport Council 2011, National Road Safety Strategy 2011-2020, p. 25, viewed 25 July 2013,

ii Transport for NSW, New South Wales Government 2013, Fatigue, viewed 29 July 2013,

iii Department of Planning, Transport and Infrastructure, Government of South Australia 2012, Road Safety: Driver Fatigue, viewed 25 July 2013,

iv Canterbury City Council 2012, Driver Fatigue, viewed 25 July 2013,

v Australian Transport Safety Bureau, Department of Transport and Regional Services, The Australian Government, 2002, Fatigue-related crashes: An analysis of fatigue-related crashes on Australian roads using an operational definition of fatigue, viewed 25 July 2013,

vi Centre for Accident Research & Road Safety - Queensland 2011, State of the Road: Fatigue, viewed 25 July 2013, and alerts/campaigns/fatalfive/documents/fatigue_fs.pdf

vii Transport Accident Commission, Victoria 2009, Fatigue statistics, viewed 25 July 2013,

viii Transport for NSW, New South Wales Government 2013, Fatigue, viewed 29 July 2013,

ix Mercedes-Benz 2013, New: E-Class Coupé and Cabriolet, viewed 25 July 2013,