Safety of the Intended Functionality of External Human Interfaces: Gaps and Research Agenda

Next-generation human-computer interactions comprise the interactions that are expected to take place between e.g., pedestrians and the so-called External Human-Machine Interfaces (EHMIs). EHMIs are expected to replace the in vehicle Driver-oriented Driver-Machine Interface in the context of high automation levels, where the driving task is fully automated. In this context, it is paramount to ensure absence of unreasonable risk due to hazards resulting from functional insufficiencies of the intended functionality or its implementation, i.e., Safety Of The Intended Functionality (SOTIF), defined in ISO 21448:2022. ISO 21448:2022 has been applied to ensure the Safety Of The Intended Driver-Machine Interface-Functionality. SOTIF does not include any specific consideration to address the so-called External Human-Machine Interface. Hence, in this position paper, we posit that the functional insufficiencies shall also embrace the socio-technical issues that might emerge in the extended automated driving system's ecosystem. These issues include faulty interactions with pedestrians, traffic-lights, and more broadly, by taking a vehicle to everything perspective (VtoX), with everything.