Consensus Building in Level 4 Automated Driving Field Trials Through Assurance Cases
摘要
Real-world deployments of SAE Level 4 (L4) automated driving vehicles require consensus among diverse stakeholders to ensure safety and dependability. We report practical insights from an L4 minibus field trial in Japan, led by TIER IV, an automated driving startup. A Safety Status Report supplements a GSN-based assurance case with plain-language explanations and highlights residual risks, offering a transparent snapshot of the current safety status rather than claiming complete safety. We linked operational data, risk analyses, and stakeholder feedback to the GSN model, captured newly identified hazards and defeaters, and revised both the report and operational plan accordingly. An anonymous questionnaire then gauged stakeholder agreement on safety goals and strategies. Building on this experience, we propose a stakeholder-oriented communication framework that couples the Safety Status Report with the questionnaire. We also introduce a lightweight Consensus Score to quantify stakeholder agreement. Our results show that concisely summarized GSN-based arguments foster shared understanding of risks and mitigations, thereby enhancing stakeholder acceptance of L4 deployments.