Vehicle-To-Pedestrian Communication Feedback Module: A Study on Increasing Legibility, Public Acceptance and Trust

Vehicle pedestrian communication is extremely important when developing autonomy for an autonomous vehicle. Enabling bidirectional nonverbal communication between pedestrians and autonomous vehicles will lead to an improvement of pedestrians' safety in autonomous driving. If a pedestrian wants to communicate, the autonomous vehicle should provide feedback to the human about what it is about to do. The user study presented in this paper investigated several possible options for an external vehicle display for effective nonverbal communication between an autonomous vehicle and a human. The result of this study will guide the development of the feedback module in future studies, optimizing for public acceptance and trust in the autonomous vehicle's decision while being legible to the widest range of potential users. The results of this study show that participants prefer symbols over text, lights and road projection. Additionally, participants prefer the combination of symbols and text as interaction modes to be displayed if the autonomous vehicle is not driving. Further, the results show that the text interaction mode option "Safe to cross" should be used combined with the symbol interaction mode option that displays a symbol of a walking person. We plan to elaborate and focus on the selected interaction modes via Virtual Reality and in the real world in ongoing and future studies.