Driver’s Mental Workload Measurement Concerning Cognitive Channels

With the development of automated driving technologies, human factors in the automated driving domain are getting more and more attention for a balanced implementation in commercial vehicle models. One influential human factor is mental workload. The driver's mental workload is crucial for driving safety; if the driver is under too high mental workload, he/she cannot execute proper action timely. In the proposed model, the mental workload is affected by different cognitive channels: visual, spatial, and verbal. In this paper, the relationships among different cognitive channels concerning the driver's mental workload are studied in a driving simulator experiment. Physiological data (pupil diameter), secondary task performance, and NASA-TLX are used for the mental workload measurement. The results show that during manual driving, the driver's mental workload in the visual cognitive channel is the highest, followed by the mental workload in the spatial cognitive channel, and the mental workload in the verbal cognitive channel is the lowest.