Combining internal and external communication: The design of a holistic Human-Machine Interface for automated vehicles

Versteggen, R., Gao, R., Bernhaupt, R., Bazilinskyy, P., Martens, M. H.

Proceedings of International Conference on Applied Human Factors and Ergonomics (AHFE). Nice, France (2024)

ABSTRACT In this paper, we explore the field of holistic Human-Machine Interfaces (hHMIs). Currently, internal and external Human-Machine Interfaces are being researched as separate fields. This separation can lead to non-systemic designs that operate in different fashions, make the switch between traffic roles less seamless, and create differences in understanding of a traffic situation, potentially increasing confusion. These factors can limit the adoption of automated vehicles and lead to less seamless interactions in traffic. For this reason, we explore the concept of hHMIs, combining internal and external communication. This paper introduces a working definition for this new type of interface. Then, it explores considerations for the design of such an interface, which are the provision of anticipatory cues, interaction modalities and perceptibility, colour usage, building upon standardisation, and the usage of a singular versus a coupled interface. Then, we apply these considerations with an artefact contribution in the form of an hHMI concept. This interface communicates anticipatory cues in a unified manner to internal and external users of the automated vehicle and demonstrates how these proposed considerations can be applied. By sharing design considerations and a design concept, this paper aims to stimulate the field of holistic Human- Machine Interfaces for automated vehicles.