External HMIs and Their Effect on the Interaction Between Pedestrians and Automated Vehicles

This paper presents a study where different types of external Human Machine Interfaces (eHMIs) are used to communicate the system state of a highly automated vehicle (SAE Level 5) that shows the intention to give right of way to pedestrians. In an interactive online survey with embedded videos for a pedestrian crossing scenario, the participants, placed in the ego perspective of the crossing pedestrian, had to decide whether they want to cross or not in regard to the equipment status of the vehicle (with eHMI vs. without) and how the system state was communicated (command vs. affirmative). The statistical analysis revealed slight tendencies within the eHMI types. Significant differences were found regarding the comparison between the implicit (no eHMI) and explicit (with eHMI) condition of the communication in the crossing frequency and the reaction time.