Directability, eye-gaze, and the usage of visual displays during an automated vehicle handover task

Abstract

The proposed next step in semi-automated vehicle technology is to allow a driver to conduct secondary tasks whilst automation is in full control of the driving task. The driver may be required to take control and promptly re-enter ‘the control loop’ if an automated feature reaches a design, geographical or capability boundary. In these circumstances it is of importance to raise the ‘Situation Awareness’ (SA) of the system through transactions between driver and vehicle. Communication literature suggests that a useful method for facilitating interactions between driver and automation is ‘directability’, guidance towards future actions or relevant pieces of information (e.g. road hazards). It is proposed that this would lead to improved SA. This study evaluated the role of directability in semi-automated vehicles by testing two research questions, how well can vocal communication from an automated assistant guide driver visual gaze, and how do drivers utilise visual displays during handover and manual driving? Participants took part in a simulated driving handover task on a highway. It was found that vocal guidance was effective in directing visual gaze. Further, the majority of visual-gaze in both handover and manual tasks was directed towards the road environment, and displays close to the road-view. This study provides additional evidence that vocal communication could serve as a reliable SA raising method, as well as provide insights into how different visual displays can be utilised for raising SA in level 3 and 4 automated vehicles.