Supporting Driver Situation Awareness for Autonomous Urban Driving with an Augmented-Reality Windshield Display

Urban traffic environments can create unpredictable hazardous situations. Even future, highly reliable automated cars (ACs) could be forced to execute sudden, surprising maneuvers causing driver discomfort and possibly a loss of trust. A counter measure might be to support driver situation awareness (SA) in such scenarios. We simulated an explanatory windshield display (WSD) interface for ACs to increase driver SA in a mixed-reality driving simulation. The interface combines screen-fixed elements and world-registered augmented reality (AR) overlays. We conducted a user study to evaluate the interface in which participants encountered critical urban driving situations and answered SA test questions during on-line freeze probes. We found a significant improvement of driver SA with the WSD interface in clear weather conditions (medium effect) as well as in bad visibility conditions (large effect).