The results of a world-first study into heavy vehicle driver fatigue revealed that reliable predictors of drowsiness and fatigue are slow eye and eyelid movements, longer blink duration and prolonged eye closure.
The study by The National Transport Commission (NTC) and the Cooperative Research Centre for Alertness, Safety and Productivity (Alertness CRC) also confirmed a scientific link between alertness and drowsiness patterns linked to specific work shifts for heavy vehicle drivers.
The scientific study spanning 2 years evaluated alertness monitoring technology and the effects of work shifts on driver alertness.
The study involved analysis of shift start times, number of consecutive shifts, shift length, shift rotation, rest breaks and their likely impact on driver drowsiness and fatigue.
More than 300 heavy vehicle driver shifts both in-vehicle and in a laboratory were involved in the research, as well as 150,000 samples of retrospective information.
NTC CEO Dr Gillian Miles said the findings would inform future fatigue policy as part of the review of the Heavy Vehicle National Law (HVNL) being led by the National Transport Commission (NTC).
“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,” Miles says.
The study found that the greatest alertness levels can be achieved under current standard driving hours for shifts starting between 6am- 8am, including all rest breaks.
It is also noted that the report’s conclusions are positive for systems that measure eye movements.
“This sequence of projects has validated ocular based alertness monitoring technology, confirming its ability to identify drowsiness related driving impairment, and provided unique objective evidence regarding heavy vehicle driver schedule features that enable safe driving with high alertness levels and features that lead to high levels of drowsiness,” it states.
According to the study the following factors increase the risk of drowsiness in drivers,
- 15 hours of day driving when a driver starts a shift before 9am
- After driving at night 6-8 hours when the driver starts a shift in the afternoon or evening
- After 5 consecutive shifts when driving again for over 13 hours
- Driving an early shift beginning after midnight and before 6am
- During the first 1-2 night shifts a driver undertakes and during long night shift sequences
- After a backward shift rotation (from an evening, back to afternoon, or an afternoon back to a morning start)
- Nose-to-tail shifts where a seven-hour break only enables five hours of sleep
Click here for the study’s summary report.