Long automated driving phase affects take-over performance

The authors investigated the impact of automated driving phases of different durations (long versus short) on take-over performance and driver state. About 30 participants drove on a dynamic simulator under autonomous mode for three successive periods of automated driving: a short (10 min), a long (1 h) and another short (10 min) period, each ending with a take-over request. They performed a non-driving task, watching a film of their choice, throughout the autonomous phases. Driving performance – reaction time and quality – and driver drowsiness were assessed at each take over. About 1 h of automated driving affected the driver's behaviour, leading to poorer take-over performance (longer reaction time and sharper avoidance manoeuvre) and increased drowsiness compared with a shorter autonomous period. Results also suggest that sequencing the autonomous phase in several short periods should improve the driver's take-over performance and help prevent drowsiness. Their findings sound a warning on the risks associated with long phases of automated driving. In particular, they provide evidence that a series of short periods of automated driving is preferable to a long, continuous automated driving phase.