Heavy vehicle driver fatigue study results to inform law

A major study into heavy driver vehicle fatigue has identified when the greatest levels of driver alertness and fatigue can occur, and will inform future fatigue policy as part of a review of Heavy Vehicle National Law.

The two-year scientific study by the National Transport Commission (NTC) and the Cooperative Research Centre for Alertness, Safety and Productivity (Alertness CRC) evaluated alertness monitoring technology and the impacts of work shifts on driver alertness. It analysed shift start time, the number of consecutive shifts, shift length, shift rotation, rest breaks and their likely impact on driver drowsiness and fatigue.

The research involved a study of more than 300 heavy vehicle driver shifts both in-vehicle and in a laboratory, as well as 150,000 samples of retrospective data, said Alertness CRC Associate Professor Mark Howard.

“We found that slow eye and eyelid movements, longer blink duration and prolonged eye closure are reliable predictors of drowsiness and fatigue,” Associate Professor Howard said.

The study also confirmed the scientific link between alertness and drowsiness patterns associated with specific work shifts for heavy vehicle driving.

NTC Chief Executive Officer Dr Gillian Miles said these findings will inform future fatigue policy as part of the NTC-led review of the Heavy Vehicle National Law (HVNL).

“This is critical new evidence that will ultimately help to decrease heavy vehicle fatigue risk at a time when the nation’s freight task is expected to double by 2030,” Dr Miles said.

The research found that the greatest alertness levels can be achieved under current standard driving hours for shifts starting between 6 am and 8 am, including all rest breaks.

Greatest risk of an increase in drowsiness occurs:

• after 15 hours of day driving (when a driver starts a shift before 9 am);
• after six to eight hours of night driving (when a driver starts a shift in the afternoon or evening);
• after five consecutive shifts when driving again for over 13 hours;
• when driving an early shift that starts after midnight and before 6 am;
• during the first one to two night shifts a driver undertakes and during long night shift sequences;
• when a driver undertakes a backward shift rotation (from an evening, back to afternoon, or an afternoon back to a morning start);
• after long shift sequences of more than seven shifts;
• during nose-to-tail shifts where a seven-hour break only enables five hours of sleep — a duration previously associated with a three-fold increased risk for motor vehicle accidents.
   

The Alertness CRC conducted the research as part of a wider collaboration including the NTC, the Australian Government, Transport for NSW, Austin Health, Monash University, the Institute for Breathing and Sleep and the heavy vehicle industry.

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