Fatigue plays a crucial role in road crashes, but a fatigue risk management specialist says it is seriously under-reported and not recognised as a contributing factor to many crashes.

A road crash, for example, is deemed to be fatigue-related if the driver has fallen asleep at the wheel. This has been reported as high as 33 per cent of single-vehicle crashes, said Dr Nicholas Mabbott, director of Beyond Midnight Consulting and author of The Wonder of Sleep.

“However, this does not account for the fact that fatigue impairment causes poor decisions and delayed responses to critical events,” said Mabbott, who gave an example of a poor decision that involves pulling out into a T-intersection and incorrectly assuming the gap in traffic was big enough at the speed limit on that roadway.

“At 100km/h, a vehicle is travelling at 27.8 metres per second. Get that wrong by one second, and you are ‘T-boned’, and the crash will almost certainly be fatal. This will not be recorded as a fatigue-related crash – simply put down as a poor decision,” said Mabbott, who was speaking ahead of an AIHS webinar on road fatalities and fatigue risk management, which will be held on Thursday 28 November 2024 from 12:00 to 1:00pm AEDT.

Another fatigue impairment is ‘driving without awareness’, where the driver can maintain reasonable lane-tracking, but cannot process any critical visual signals more than a few metres ahead,” said Mabbott.

“In training, I refer to this stage as ‘The lights are on, but no-one is home.’ If a child walks onto the road, wildlife bounces over the road, or a cyclist is within the left edge of the lane, they are all likely to be struck with no avoidance manoeuvre.”

‘Driving without awareness’ occurs as the human brain is closing down attempting to get to sleep. The reason for this is the brain is low in fuel for neurons, and sleep recycles the brain energy to produce the fuel it needs to perform well.

“The brain has a hierarchy of needs and unfortunately, the need to obtain more energy for the neurons is higher on the list, than it is to keep the person safe. This is why most drivers have had microsleeps (or longer sleeps) while driving,” said Mabbott.

There are significant WHS implications in this for organisations, and he said the resources sector, aviation and emergency services such as police and fire, generally have well-designed fatigue risk management plans and procedures.

“Most do it well, with input from subject matter experts in the fields of sleep and fatigue management. Of the 34,000 employees that I have delivered training to, around 32,000 have been from the resources sector, as they are aware of the risk, and they care for their people,” said Mabbott.

“Many other groups need to do better, but they often don’t recognise the risk adequately. For example, if they don’t do nightshift, they believe there is no, or little fatigue risk. This could not be further from the truth, as dayshift workers often suffer from poor sleep.

“This is why we see so many incidents and ‘burn-out, from employees in different occupations. I would like to name some of the occupations that need to do better, but I won’t. If you look at the statistics on workplace incidents, you will almost certainly find that those high in incident numbers, are poor at both managing fatigue and educating their employees on managing sleep and fatigue.”

Mabbott said the most common challenge is a lack of awareness of the importance of sleep which underpins fatigue outcomes. “Many occupations feel that if they reduce the amount of time on tasks, they have fatigue covered. But this is only part of the equation,” he said.

“Further, around 20 per cent of your employees will give around 80 per cent of the fatigue alarms (or incidents). Having a ‘sleep improvement program’ can seriously enhance overall safety at a workplace.”

The most common misconception Mabbott has seen is that “we need to drive a long way to become fatigued”, said Mabbott, who has analysed fatigue crashes for the WA Police major crash investigation division and handled 18 cases thus far.

Only three of these cases had a driver who has been awake for over 17 hours and have driven a long way and had a micro-sleep at the wheel. Mabbott said the most common statistic has been that 12 of the 18 crashes have involved a driver who has obtained 5.5 or less hours of sleep before the drive, while ten of the crashes had passengers asleep at the time.

Such misconceptions require a “reframing”, according to Mabbott, who said a good place to start is the thought process behind ‘journey management plans’. “These are wisely structured to reduce fatigue risk for employees driving an hour or more to, or from work. While this is important, many fatigue crashes occur well within the first hour of driving,” he said. Journey management plans should continue to be used but need to include:

• All employees who drive (no matter how far)
• Sleep needs to be included as a major risk factor
• Any shift worker, as their circadian rhythm is usually highly affected, and recovery sleep is often inadequate during the day
• All employees should be appropriately educated in sleep and fatigue management. Sometimes the risk is at work, and most times, the biggest risk is driving to and from the workplace

Another misconception in need of reframing is that employees should stop when they feel fatigued and take a break. “Unfortunately, my experience with peoples’ perception of the term ‘fatigue’, is that they must be almost falling asleep to be fatigued,” said Mabbott, explained that the term ‘fatigue’ can be broken down into three levels of driving impairment caused by having inadequate fuel left in the brain. They are:

1. “Tired” – just a bit bored and slightly fidgety. Eyes may be a little scratchy from not enough blinking. “A two-minute break, stretching and moving will return you to good levels of activity and performance,” said Mabbott.

2. “Drowsy” – that feeling where you can’t remember the last few kilometres, your eyes are hard to keep open and your driving performance may be called out by a passenger. “This is in fact, the beginning of stage one sleep, where the brain prepares you to lay down and sleep. It is occurring due to having insufficient brain energy left and the brain attempts to get to sleep to recycle more energy,” he said.
“At this point a driver is likely to have one or two, two- to five-second micro-sleeps. These are often not recognised, unless a passenger witnesses it, or an incident occurs. The best control is to find a safe and secure spot to pull over, get in the back seat and set a timer on your phone for a 20-minute nap.”
Mabbott recounted the stories of two drivers who tried to do the right thing when they were drowsy and pulled over for a couple of minutes to stretch and get some air. “Unfortunately, this did not recycle brain fuel and both drivers went on to have fatal fatigue crashes within the next fifteen minutes,” he said.

3. “Sleepy” – this is the endpoint of driving fatigued, where the person falls into true sleep (not a microsleep). In these cases, a driver can go off the road for several seconds before the bumpy terrain (or striking objects) wakes them. “These are often fatal crashes. Only a 20-minute nap, or a longer 90-minute sleep cycle plus eating, drinking and stretching can fix this level of fatigue,” he said.

The best reframing possible is the notion of “stop before you get tired”, said Mabbott. If an employee is educated about the benefits of eating healthy, moving often (any exercise is good) and sleeping well (including fixing any sleep disorders), he said there is often clear improvements in safety as well as health and longevity.