Effect of Directional Auditory Takeover Request on Takeover Behavior and Eye Movement in Conditionally Automated Driving

Conditionally automated driving (CAD) systems allow the driver to temporarily disengage from driving tasks. The significant concern of CAD is to ensure a safe and timely transition to the manual driving mode when the system exceeds its limits and issues a takeover request (TOR). The aim of this study was to investigate the effect of directional auditory TOR on the driver takeover process. A within-subject experimental design was used: twenty-four participants drove four times in an automated driving simulation scenario and received two non-directional auditory TORs and two directional auditory TORs (TOR directions corresponding to the orientation of potential hazards). The takeover behavior and eye movement characteristics relevant to the takeover process were collected. The results showed that directional auditory TOR enabled drivers to shift their visual attention to the hazards' area faster than non-directional auditory TOR, accelerating the driver's understanding of the road environment and improving takeover behavior. The study may provide a reference for the design of takeover requests for conditionally automated driving.