How different mental workload levels affect the take-over control after automated driving

Automated driving represents a new way of driving and, therefore, significant changes in driver behaviour are expected. In this study, we analysed the impact of different levels of mental workload associated with a non-driving task in response to a take-over request (TOR). Thirty participants drove in a driving simulator through three experimental conditions: once in manual driving and twice following an automated driving during which a non-driving task was performed. The impact of the mental workload was evaluated by manipulating the mental workload induced by the non-driving task (low versus high mental workload). The results showed a negative effect of automated driving on take-over performance regardless of the level of mental workload. These results point out that engagement in non-driving task leads to reduced situation awareness. Interpretations of results and research prospects are discussed.