The Car That Cried Wolf: Driver Responses to Missing, Perfectly Performing, and Oversensitive Collision Avoidance Systems

Automated emergency braking (AEB) systems-which alert a driver to approaching hazards and automatically brake-are currently available in some vehicles and will soon be widespread. Due to the uncertainties inherent in any environment and difficulties in processing sensor data, these systems are prone to both false alarms and system misses of hazards. A pressing design concern is whether to bias these systems toward a higher likelihood of false alarms versus system misses for non-fatal events. We investigated how drivers form mental models of the AEB system and how that influences their reliance on the system during a critical, potentially fatal, failure. In a full vehicle driving simulator, participants experienced nine interactions that reflected the system's level of bias toward false alarms or toward misses for non-fatal events or that demonstrated perfect performance. When a potentially fatal event occurred, participants trained to expect misses were better able to avoid a pedestrian in the road after a detection failure than those using a system with perfect performance or false alarms. These findings suggest that systems biased toward misses in non-fatal events encourage driver vigilance and preparedness for potentially fatal events.