This chapter presents a background to the concept and measurement of mental workload. An examination of the various elements of the driving task and the cognitive skills and abilities required to perform these elements reveals the complexity of the mental workload and the problems in its measurement. Driving task elements considered include vehicular guidance, navigation, communications, social environment, the operation and monitoring of systems and command decisions. Individual driver characteristics (age, driving experience, physical and mental state) and environmental factors (temperature, noise, vibration, social interaction) are also examined. Mental workload research specific to cars is reviewed. Areas covered include primary task studies, secondary task studies, behavioural studies, subjective ratings, verbal protocols and physiological measures. The implications of driver mental workload for future vehicle desgn is discussed.
Abstract