Driver-initiated take-overs during critical evasion maneuvers in automated driving

The aim of the current study is to investigate predictors and consequences of driver-initiated take-overs during automated evasion maneuvers. Literature on control transitions in automated driving has mainly focused on system-initiated take-overs. However, drivers may also initiate take-overs without take-over requests. To date, such driver-initiated take-overs have rarely been investigated. Our study addresses this research gap. In a driving simulator study with 61 participants, we investigated whether the criticality of highly dynamic evasion maneuvers and trust in automation affect the probability of driver-initiated take-overs. Criticality was manipulated via time headway (THW) and traction usage (TU). Trust was varied by manipulating automation reliability before the experimental trials. Consequences of driver-initiated take-overs in terms of collisions and lane departures were assessed. The results indicate that THW, TU, and trust affect the probability of driver-initiated take-overs. Moreover, the time it takes the automation to respond to an obstacle ahead by starting an evasion maneuver may be another relevant factor in predicting take-overs. After a take-over, drivers produced a number of unnecessary lane departures and collisions. These were independent of THW and TU. The study demonstrates that drivers are more likely to take over vehicle control during automated evasion maneuvers without take-over requests when criticality increases and trust in automation decreases. Such take-overs may be hazardous for traffic safety. Our findings help to design automated vehicles that avoid unnecessary take-overs in critical driving situations or de-escalate their consequences effectively, thus increasing traffic safety.