Fitness to Drive… Driving Tired?

17 Sep Fitness to Drive… Driving Tired?

Commentary on An Objective Measure of Drowsy Driving: Are We There Yet?

Recent studies, which included examining brain activity, have shown that sleep-deprived drivers are more likely to experience lasting or momentary losses of alertness behind the wheel, making it difficult to maintain the lateral position of the vehicle on the road. Dr Rizzo gives us a commentary on some Australian research from the University of Queensland that helps to establish an objective measurement of sleepiness in otherwise healthy individuals while driving by examining eye-closure parameters.

Dr Soleimanloo (UQ) and colleagues’ work highlights that drivers often combine sleep deprivation and driving, which is associated with injury and death on the road. Importantly they identified “time-on-task” relationship to risk also, i.e. driving for long periods. Also they also showed that this daytime drowsiness induces lateral deviations during driving, which are circumstances that lead to motor vehicle accidents.

Dr Rizzo points out that while this study does contribute to our understanding of measuring driver sleepiness, it doesn’t separate fatigue from sleepiness. For example, what role does fatigue play in the “time-on-task” relationship to drowsy driving? Also that despite this study, we are yet to identify a clear-cut threshold beyond which driver error is likely to occur. More research like this is needed if we are to establish safe parameters for driving while tired and fatigued.


Rizzo D, Baltzan M. An objective measure of drowsy driving: are we there yet? J Clin Sleep Med. 2019;15(9):1191–1192.

Original article:

Shekari Soleimanloo S, Wilkinson VE, Cori JM, et al. Eye-blink parameters detect on-road track-driving impairment following severe sleep deprivation. J Clin Sleep Med. 2019;15(9):1271–1284