Driving performance, sleepiness, fatigue, and mental workload throughout the time course of semi‐automated driving—Experimental data from the driving simulator

Abstract

AbstractAutomation offers the potential to mitigate or reduce the risks related to driving. There are some new challenges for drivers related to semi‐automated driving. Some of them are associated with suboptimal mental workload or prolonged need for sustained attention. This paper presents the results of an experiment investigating differences in manual driving before and after the automated phase in the scenario simulating a time‐course of semi‐automated driving. Sample size: 52 participants with two experimental sessions each day and night session. The experiment used a driving simulator to create a semi‐automated driving scenario comprising manual driving, the automated phase, and manual driving. The following questionnaires were collected: Karolinska Sleepiness Scale, Take‐Over Readiness Scale (developed for this research project, included in Appendix), Samn–Perelli Fatigue Scale, and NASA‐TLX. Driving performance significantly decreased after the automated phase (e.g., standard deviation of the steering wheel angle was 255.73 before vs. 287.11 after automation) and the effect was more profound during the night. Participants were sleepier and more fatigued after the automated phase, and assessed mental workload as lower. The results of the questionnaires did not correlate with driving performance. The results of the experiment suggest that manual driving could deteriorate after the automated phase, and that driver might not be able to assess their fitness to drive at the moment of take‐over of manual driving.