Impact of central rail traffic supervision stations on safety.

Summary Although currently considered as not safe (the safety functions being ensured by other subsystems), rail traffic supervision systems can contribute to safety in certain crisis scenarios where an adapted decision of a supervision operator could significantly reduce the severity of accident scenarios. It is therefore of utmost importance to identify such scenarios in order to consider future supervision systems with a view to further improving traffic safety. Since supervision involves decisions made by humans, it is essential to take the human factor into account. The study focuses on the evaluation of the human-machine interaction and its impact on safety. Specific studies of the human factor were carried out on a railway traffic supervision platform installed in the premises of the UTC. The objective of the experiments is to obtain information on the general cognitive processes involved in the management of a dynamic environment of mobile traffic and to contribute to the evaluation of the supervision system in a situation of use by operators confronted with the management of a nominal, normal and degraded situation. An interdisciplinary approach has been proposed in order to have a common model between specialists of human and social sciences and specialists of operational safety. This frame of reference was drawn from a systemic perspective of the study of safety thanks to the Functional Resonance Accident Model method. Two case studies illustrate the proposed approach.