“What’s the Robo-Driver up to?” Requirements for Screen-based Awareness and Intent Communication in Autonomous Buses

Autonomous buses are expected to become a cornerstone of future mobility systems. Especially during their introduction, passengers may require reassurance about the vehicle’s awareness of the situation on the road and of its intended next actions to further acceptance. In order to investigate the need and requirements for information about the vehicle’s awareness and intent from the perspective of first-time users, we conducted two user studies in a state-of-the-art autonomous bus at public demonstration spaces. In the first study, participants underwent a demonstration ride with the bus and were then asked about their needs for awareness and intent communication. The second study took participants on a ‘simulated ride’ within a stationary bus, in which typical scenarios of the road ahead were presented, together with different awareness and intent cues. Our results suggest that, first, future autonomous bus passengers may be in need of such awareness and intent communication screens. Second, we found that awareness and intent communication may be of greater importance for the indication of potential hazard recognition than for indicating route directions. Third, due to their complementary strengths, none of the three compared types of visual communication (text, icon and augmented reality) should be used in isolation.