Communication of Automated Vehicles and Pedestrian Groups: An Intercultural Study on Pedestrians’ Street Crossing Decisions

Abstract

Implicit as well as explicit cues are means of communication in driver-pedestrian interaction. With the introduction of automated vehicles (AVs), drivers can engage in non-driving related activities which rise new challenges of communication between AVs and pedestrians. In this context, external human-machine interfaces (eHMIs) are seen as a key contribution in building pedestrians’ trust towards AVs by enabling communication between them. However, a research gap exists regarding the communication of AVs and pedestrian groups. In an intercultural study we investigated the impact of the variables eHMI concept and group size on pedestrians’ street crossing decisions regarding (1) willingness to cross and (2) trust in AVs. Therefore, German (N = 126) and Chinese (N = 79) participants took part in an online-based video study. The results showed that a "walking person" eHMI had more stable effects with respect to the dependent variables in comparison to a "smiling face" eHMI in both countries. No main effect of group size on a pedestrian’s willingness to cross or trust in AVs was found. Nevertheless, qualitative data indicated an effect of group size in pedestrian-AV communication processes. Our results therefore contribute to the investigation of communication between AVs and pedestrian groups.