Fatigue is one of the three main causes of death and injury on our roads. From 2013 to 2017, more people in NSW died in fatigue-related crashes than drink driving crashes. In Narrandera Shire there were 19 fatigue crashes with two fatalities and 10 serious injuries. Fatigue-related crashes are twice as likely to be fatal - drivers who are asleep can't brake.
As Christmas and the holiday season rapidly approaches it is not uncommon for life to get busier than usual. Often there are more social events, tasks that need to be finalised at work, extra jobs to do around the house in preparation for guests or parties and the list goes on. Many of us can tend to burn the candle at both ends and sacrifice our sleep leading to a sleep debt.
We all need about eight hours of sleep a night to function effectively. When we reduce the amount we sleep at night, we start to accumulate a sleep debt. It’s the difference between the hours of sleep you need and the hours you get. When we have sleep debt, our tendency to fall asleep the next day increases. The larger the sleep debt, the stronger the tendency to fall asleep – including when you are driving. Sleep debt can only be erased by having more sleep.
Having a sleep debt impacts on our ability to drive and increases the risk of a microsleep. Research has shown being awake for about 17 hours has a similar effect on performance as a blood alcohol content of 0.05.
A microsleep is a brief and unintended episode of sleep. Microsleeps commonly occur when you try to stay awake while performing monotonous tasks, including driving. Microsleeps can last from a fraction of a second to a few minutes. During a four-second microsleep, a car travelling at 100 km/h will travel 111 metres while completely out of the driver’s control.
Often we associate fatigue related crashes with long drives particularly at night. Although this is certainly a risk it is important to remember that fatigue-related crashes can happen on any trip no matter how long or short or what time of day. For example, fatigue crashes can occur on a short drive home after a long day’s work.
There are two other key sleep factors that impact driving – circadian rhythms and sleep inertia. Sleep inertia, the feeling of grogginess you experience after waking, can affect your ability to perform even simple tasks which is dangerous for people who drive shortly after waking from sleep. It is usually reversed within 15 minutes however it can last up to four hours.
Our circadian rhythms, which influence when our body wants to sleep, can lead to impaired performance, including our ability to drive, during the night and afternoon siesta hours. Older drivers tend to have more fatigue-related crashes during the afternoon siesta hours. Younger drivers tend to have more fatigue-related crashes during the night.
To keep everyone safe think about how tired you are before driving, recognise the early warning signs when driving and avoid driving tired. The best way to avoid driving tired is to make sure you have enough sleep before driving, regardless of the length of your trip.
There are great tips to avoid driving tired on the Centre for Road Safety website www.roadsafety.transport.nsw.gov.au. Most importantly remember sleep is the only way to overcome tiredness.
