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

Autonomous buses are expected to be a cornerstone of future sustainable and acceptable mobility systems. Es-pecially during the transition phase towards their large-scale roll-out, passengers may need further reassurance about the vehicle´s awareness of the situation on the road and of its intended next actions. In order to investi-gate the suitability of advanced dynamic information screens for such purposes, we conducted two survey stud-ies in an operating autonomous bus. First, our results suggest that a large portion of future autonomous bus passengers may be in need of such advanced dynamic information screens. Second, we found that awareness and intent communication may be more required for indicating potential hazard recognition than for indicating route directions. Third, none of the three compared types of visual communication - text, icon and augmented reality - should be used in isolation, as preferences widely varied among users and complementary strengths became obvious. In this respect, we provide guidance on suitable combinations of these modes, the use of fur-ther design elements and recommend further research directions.