Keeping in the lane! Investigating drivers’ performance handling silent vs. alerted lateral control failures in monotonous partially automated driving

This study investigated how drivers can manage the take-over when silent or alerted failure of automated lateral control occurs after monotonous hands-off driving with partial automation. Twenty-two drivers with varying levels of prior ADAS experience participated in the driving simulator experiment. The failures were injected into the driving scenario on curved road segments, accompanied by either a visual-auditory alert or no change in HMI. Results indicated that drivers could rarely maintain lane-keeping when automated steering was disabled silently, but most drivers safely managed the alerted failure situation within the ego-lane. The silent failure yielded significantly longer take-over time and generally worse lateral control quality. In contrast, poor longitudinal control performance was observed in alerted conditions due to more brake usage. An expert-based controllability assessment method was introduced to this study. The silent lateral failure situation during monotonous hands-off driving was rated as uncontrollable, while the alerted situation was basically controllable. Participants showed their preferences for the TORs, and the importance of conveying TOR reasons was also demonstrated.