In this paper we present a safety argument fragment to contribute towards solutions to several key factors of relevance towards deployment of safe Automated Driving Systems (ADSs). Firstly, we address the need for exhaustive safety requirements by considering vehicle level, quantitative safety requirements. Secondly, situation awareness is employed to dynamically adapt the ADS’ decision-making. Thirdly, the ADS’ situation awareness is extended with constraints following Precautionary Safety (PcS) principles to ensure the fulfilment of the quantitative safety requirements. Fourthly, the models and assumptions supporting steps two and three are ascertained through the use of an operational design domain, which the ADS is designed to operate within. Furthermore, the paper contrasts the proposed argument with the state of the art in safety assurance to identify the key challenges still remaining.