Obstacle avoidance under automated steering: Impact on driving and gaze behaviours

- Resuming manual control from highly automated vehicle to avoid an obstacle is uneasy.
- Highly automated driving modifies visual scanning of the driving environment.
- Drivers disengage visually from the steering task with highly automated driving.
- Resuming manual control is a problem of both visual scanning and action performance.

Within the context of more and more autonomous vehicles, an automatic lateral control device (AS: Automatic Steering) was used to steer the vehicle along the road without drivers' intervention. The device was not able to detect and avoid obstacles. The experiment aimed to analyse unexpected obstacle avoidance manoeuvres when lateral control was delegated to automation. It was hypothesized that drivers skirting behaviours and eye movement patterns would be modified with automated steering compared with a control situation without automation. Eighteen participants took part in a driving simulator study. Steering behaviours and eye movements were analysed during obstacle avoidance episodes. Compared with driving without automation, skirting around obstacles was found to be less effective when drivers had to return from automatic steering to manual control. Eye movements were modified in the presence of automatic steering, revealing further ahead visual scanning of the driving environment. Resuming manual control is not only a problem of action performance but is also related to the reorganisation of drivers' visual strategies linked to drivers' disengagement from the steering task. Assistance designers should pay particular attention to potential changes in drivers' activity when carrying out development work on highly automated vehicles.