Bringing the Driver BackIn-The-Loop: Usefulness of Letting the Driver Know the Duration of an Automated Drive and its Impact on Takeover Performance

A critical challenge of higher levels of automated driving (SAE level 3) is the reengagement of the driver to take back manual control. In this study we investigated to what extent the driver could be helped by receiving information about the duration of the automated driving as well as the available time for the reengagement. To address this research question, we conducted a simulator study where 41 participants drove alternating in manual mode and automated mode. Audiovisual cues informed the participants about the take-over 15 seconds in advance. The cockpit display showed different types of duration: takeover time, automated driving time and their combination. We compared the perceived usefulness of the prediction types, the gaze behavior during takeovers as well as driving performance. The results indicate that the combined and automated driving display type were perceived to be highly useful by the participants. This perceived usefulness is positively associated with their intention to use such a system in their daily lives. An analysis of the driver’s gaze indicates that drivers used the combined display type during more than the other display types and that drivers acquired over time a safer gaze behavior with the combined display type as they monitored the road environment more during takeovers than in the other conditions. In this paper we describe the results along with performance results and a comprehensive assessment with implications for further research.