The impact of 7-hour and 11-hour rest breaks between shifts on heavy vehicle truck drivers' sleep, alertness and naturalistic driving performance. (September 2021)

• Record Type: Journal Article
• Authors: Cori, Jennifer M.; Downey, Luke A.; Sletten, Tracey L.; Beatty, Caroline J.; Shiferaw, Brook A.; Soleimanloo, Shamsi Shekari; Turner, Sophie; Naqvi, Aqsa; Barnes, Maree; Kuo, Jonny; Lenné, Michael G.; Anderson, Clare; Tucker, Andrew J.; Wolkow, Alexander P.; Clark, Anna; Rajaratnam, Shantha M.W.; Howard, Mark E.
• Is Part Of: Accident analysis and prevention. Volume 159(2022)
• Publication Date: 2021-09
• Subjects: Driving -- Sleepiness -- Vigilance -- Shift scheduling -- Ocular alertness -- Shift work; Accidents -- Prevention -- Periodicals; Accident Prevention -- Periodicals; Accidents -- Prévention -- Périodiques; 363.106
• DOI: 10.1016/j.aap.2021.106224
• Languages: English
• ISSNs: 0001-4575

Abstract

Highlights: Heavy vehicle drivers on average had 5.1-hours sleep during a 7-hour rest break. Heavy vehicle drivers on average had 6.5-hours sleep during an 11-hour rest break. Subjective sleepiness was reduced after the 11- vs. 7-hour rest break. Objective alertness when driving was improved after the 11- vs. 7-hour rest break. Some driving performance metrics were improved after the 11- vs. 7-hour rest break. Abstract: Background: An inadequate rest break between shifts may contribute to driver sleepiness. This study assessed whether extending the major rest break between shifts from 7-hours (Australian industry standard) to 11-hours, improved drivers' sleep, alertness and naturalistic driving performance. Methods: 17 heavy vehicle drivers (16 male) were recruited to complete two conditions. Each condition comprised two 13-hour shifts, separated by either a 7- or 11-hour rest break. The initial 13-hour shift was the drivers' regular work. The rest break and following 13-hour shift were simulated. The simulated shift included 5-hours of naturalistic driving with measures of subjective sleepiness, physiological alertness (ocular and electroencephalogram) and performance (steering and lane departures). Results: 13 drivers provided useable data. Total sleep during the rest break was greater in the 11-hour than the 7-hour condition (median hours [25 th to 75 th percentile] 6.59 [6.23, 7.23] vs. 5.07 [4.46, 5.38], p = 0.008). During the simulated shift subjective sleepiness was marginally better for the 11-hour condition (mean Karolinska Sleepiness Scale [95 th CI] = 4.52 [3.98, 5.07] vs. 5.12 [4.56, 5.68], p = 0.009). During the drive, ocular and vehicle metrics were improved for the 11-hour condition (p<0.05). Contrary to expectations, mean lane departures p/hour were increased during the 11-hour condition (1.34 [−0.38, 3.07] vs. 0.63 [−0.2, 1.47], p = 0.027). Conclusions: Extending the major rest between shifts substantially increases sleep duration and has a modest positive impact on driver alertness and performance. Future work should replicate the study in a larger sample size to improve generalisability and assess the impact of consecutive 7-hour major rest breaks.