A Safety Regulatory Framework for Certification and Authorization Process of Self-Driving Cars: Experience from European Railways

Abstract

Safety improvement represents a key driver in the development of self-driving cars (SDCs). It is currently assumed that safety of SDCs should be approximately at the same level achieved by trains or airplanes. For example, the European Railway Traffic Management System (ERTMS) which oversees train speed and stopping position is compliant with a Tolerable Hazard Rate (THR) of 10-9/h/train. To guarantee this high level of safety, it is necessary to have a clearly defined regulatory framework for certification and safety approval process for SDCs with Automatically Commanded Steering Functions (ACSF). Nevertheless, many car manufacturers are relying on extensive experimental campaigns to demonstrate the achievable level of safety. This paper describes a framework for certification of SDCs based on the experience of the ERTMS authorisation process adopted for train control in Europe and accepted world-wide. This framework is built on a so-called Common Safety Method for Risk Assessment (CSM-RA) that was originally set up for management of significant safety changes in a railway system. Furthermore, the CSM Design Targets are introduced to harmonise safety requirements for SDCs with ACSF. We believe that a synergy between train and car automation leveraging on the safety primacy of the ERTMS and the mass market potential of cars is a stimulus to achieve the highest safety standards at lower costs.