Designing Emotional Expressions of Autonomous Vehicles for Communication with Pedestrians in Urban Shared Spaces: Use Cases, Modalities, and Considerations

Abstract

Autonomous vehicles (AVs) in urban environments are increasingly equipped with external human-machine interfaces (eHMIs) to interact with nearby pedestrians for safety and social needs stemming from the absent driver-pedestrian interaction, such as eye contact and hand wave. In particular when it comes to pedestrian-vehicle shared spaces, communication strategies supporting social interactions, such as emotional expression, have the potential to improve AV-pedestrian interaction. Emotional expression has been investigated for human-robot interaction but has thus far not been explored as a communication strategy for AVs. To support the integration of AVs into urban areas, especially for spaces dominated by pedestrians and shared by AVs, we investigate emotional expressions of AVs as a communication strategy, through a focus group study with twelve domain experts from Human-Computer Interaction, User Experience/User Interface Design, and Intelligent Transportation Systems to collaboratively devise use cases, modalities of emotional expressions, and design considerations. Findings of this paper contribute to designing external communication strategies for AVs in urban shared spaces and highlight avenues for future research.