Objective: The driver's instantaneous situation awareness in the process of take-over of vehicle control in automated driving has not yet been thoroughly investigated. The proposed research can provide a better understanding of the driver's perceived characteristics and identify the most urgent information requirements of the on-site scenario when the driver's eye sight returns from other distractors to the driving scene.
Methods: We conducted an experiment in simulated automated driving to study the participants' ability of instantaneous hazard perception and judgment. The scene pictures, which were displayed in millisecond time, were used to imitate the situations that drivers would see when the distracted drivers returned their gaze from the distractive sources to the road in the simulated automated driving.
Results: The results show that the driving state, scene representation time and hazard levels affect the instantaneous situation awareness of drivers. In addition, the scene perception accuracy of the group who played games during automated driving is much lower than that of the group that chatted with the copilot. The longer picture-showing duration decreases the accuracy of hazard identification, whereas the shorter picture-showing duration increases the accuracy of hazard perception and the hazard rating score.
Conclusions: In conclusion, distraction reduces the accuracy of the instantaneous scene perception of drivers, and drivers behave more cautiously in decision making when the driving situations are more hazardous. This study provides a good theoretical basis for the design of hazard warning information for automated driving.
Keywords: Automated driving; hazard level; instantaneous situation awareness; scene perception.