Towards A Holistic Communication approach-Combining eHMI and dHMI for the Interaction on a Shared Space

In the near future, automated vehicles (AV) will be introduced into mixed traffic environments and therefore will interact with different traffic participants. To guarantee a safe interaction, the AV needs to communicate future intentions and behavior especially for the interaction with vulnerable road users, e.g., pedestrians. As possible communication tool, an external Human-Machine Interface (eHMI) positioned on the outside on the vehicle is able to transmit explicit information to the surrounding traffic environment and can enhance the pedestrians’ feeling of safety and trust. Nevertheless, current research describes that pedestrians rely more on the implicit communication, e.g., vehicle’s motion patterns, which can be transmitted via dynamic Human-Machine Interface (dHMI). By highlighting the importance of explicit and implicit communication, this study should tackle the question how the interplay between both communication means should be considered in the AV’s design regarding different vehicle types. The present study aims to investigate the combination of eHMI and dHMI for two different vehicle types (car vs. bus) focusing on the interaction with a pedestrian on a shared space. In short video sequences, participants encountered both vehicles equipped with a LED light-band eHMI showing an intention-based communication strategy. The eHMI mode was varied (on vs. off) and combined with two different vehicle dynamics congruent vs. incongruent to the displayed eHMI. As the present study is work-in-progress, the data-collection process is ongoing. Results and further implications for future studies will be discussed