STPA-WA: A Safe System-Oriented Extension of STPA for Dependability in Automated Driving

To nearly achieve vision zero, the United Nations have introduced the safe system approach. This approach aims at accommodating human factors by incorporating redundancy within the different identified safety pillars (safe speed linked to reg-ulations, safe vehicles, safe roads, safe emergency care). To contribute to vision zero, ADSs (Automated Driving Systems) need to contribute to road safety, in addition to ensuring safety of the intended functionality. Achieving safe and harmonious ADSs necessitates a comprehensive safety approach beyond the vehicle-centric / ADS-centric perspective. It also calls for roadmanship which is a concept that centers on whether the vehicle plays well with others. System Theoretic Process Analysis (STPA) is a process for conducting hazards analysis. STPA has been recently included within the automotive safety standards and regulations as suggested process to be adopted. However, its application has been considered challenging and proposals for adaptations have been provided. In this paper, we provide yet another novel adaptation,called STPA-WA1, which embraces roadmanship and the different perspectives represented by the different pillars. STPA-WA deepens safety/dependability understanding.