An HMI Concept to Improve Driver's Visual Behavior and Situation Awareness in Automated Vehicle

At a level-3 or higher level automation [1], a driver does not have to constantly monitor the vehicle and environment while driving, which enables the driver to conduct non-driving-related tasks (NDRTs) and be out of the control loop. This may influence a driver's visual behavior, cognitive states, which leads to loss of situation awareness (SA) and skills. This is dangerous if the automated system reaches its boundaries: the driver must take-over the driving task in a critical situation within a limited period of time. In this paper, a concise HMI concept of the LED ambient light positioned at the bottom of the windscreen is presented, which contains information about the status and intention of the automation, detected potential hazards and the warning for a take-over request (TOR) by varying the LED's color, frequency, lighting position and animation. The goal is to increase the SA during automated driving and improve the take-over quality while allowing the driver to perform NDRTs without distraction and annoyance. In this between-subject-design experiment in a static driving simulator, 50 participants performed a visual-motoric task on a smartphone during a 45-min automated drive with or without the new HMI. Compared to the baseline, results show significant improvements in the gaze behavior and take-over quality. The new HMI also shows a high acceptance and increases the trust in automation while avoiding overtrust.