Tackling fatigue: interventions for drowsy driving
It’s been a gradual evolution in road safety over the past fifty years. Since 1970, the worst year on record, road deaths in Australia have gone down by two thirds — even though we have four times as many cars on the roads.
A driver does a roadside eye tracking assessment to detect fatigue. In the future, portable eye tracking goggles may be used by police.
This dramatic reversal was no accident. It was the result of a tenacious, research-led program of legislation, powerful communication, and road and car design that has changed driver behaviour.
One of the many lessons of these decades is that road deaths are largely predictable and preventable. More research into the systemic causes of road death and trauma is needed, but we now have strategies that have proven their value.
Clare Anderson, Associate Professor Psychology at Monash University, points out that “road-side tests for alcohol have reduced fatalities by about 35 per cent, so we know that this general deterrent model works”.
If general deterrence is such an effective strategy, where else can we apply it?
Tackling driver fatigue
Fatigue is one of the top five causes and a factor in 20-30 per cent of motor vehicle crashes. According to Associate Professor Anderson, 17-19 hours without sleep is comparable to a blood alcohol level of 0.05 per cent, and 21-24 hours without sleep is comparable to double the legal limit.
As well as this level of impairment, crashes involving a fatigued driver are more likely to be fatal, because they haven’t braked — even alcohol-affected drivers have their eyes open.
It’s a significant risk for the road transport industry, whether it’s truck drivers or other users of the road. Chain of Responsibility and other road safety regulations give organisations a legislative incentive to remove the systemic factors that keep a dangerously-fatigued driver on the road.
Linfox invests in driver training and programs to reduce the risk of fatigue and, with the help of in-cab monitoring technologies, get a driver into a safe place prior to risks emerging.
In the wider world it is harder to tackle the factors that increase the risk of fatigue in other users of the road. As part of Victorian Government’s Towards Zero Strategy, VicRoads has commissioned Monash University to carry out a four-stage project to identify a device that police could potentially use to test drivers on the side of the road.
An initial literature review narrowed the field of suitable devices, which were then trialled in the laboratory.
“The goal of the lab-stage was to find out which of these devices could reliably assess the level of sleepiness of someone who had been awake for forty hours and predict their level of impairment,” explains Associate Professor Anderson.
One of these devices, a pair of goggles that tracked eye movements, made it through the second stage and was trialled in a fully instrumented vehicle on a closed track.
A driver wears an electroencephalogram (EEG) cap to monitor brain activity and detect microsleeps while driving. Credit: Seven News.
The study monitored the brain activity of drivers behind the wheel. Credit: Seven News.
The third stage tested a driver’s level of impairment — observed in behaviour such as lane deviation, and in physiological signs such as fall asleep events while driving — after zero, three, five, and eight hours sleep.
Testing has mostly been carried out with people under the age of thirty because research shows they are most at risk of falling asleep at the wheel, according to Associate Professor Anderson. The fact that they are not experienced drivers, or trained like professional drivers, is not an issue.
"Fatigue is a physiological response and no amount of experience or training can overcome it,” she says. The fourth, and final stage of testing in the field is due to commence later this year.
“This is close. We’re testing a device that is available now in the market — it’s not a prototype. If we can show that it reliably predicts impairment, then it could potentially be put in the field for police officers to use,” says Professor Anderson.
Clare Anderson is an Associate Professor, and sleep and circadian specialist at the Turner Institute for Brain and Mental Health at Monash University.
Her research expertise is based on the impact of sleep and circadian disruption on human performance, with a particular focus on safe driving. Her leadership in the CRC for Alertness, Safety and Productivity has led to the development of biomarkers of sleep loss for future biological testing of fatigue.
She is internationally recognised for her expertise in fatigued driving, in particular the assessment of technologies for fatigue testing, and is a Scientific Advisor for the Victorian Device Impairment Working Group. Clare is a regular speaker at national and international conferences, and external organisations in relation to fatigue and safety. She consults across a wide number of business sectors in areas relating to sleep and performance, and has appeared in numerous media outlets, including print, radio and TV.