The application of the CE regulation 402/13 and the quantitative evaluation of risk to the Italian Railway 'SSC' (Supporting system for the driver) control command system

Abstract

Proper hazard analysis and risk evaluation management are the main steps to define the safety requirements of a railway control command system aiming to protect trains from their physical constraints, the limits of the infrastructure they have to run on and the traffic constraints as they share the same infrastructure with other vehicles. After a short overview of the Italian national railway control command systems, the goal of this paper is to describe the approach adopted for providing the hazard analysis to the protection system named SSC (Supporting System for the Driver - Sistema di Supporto alla Condotta) with a special focus on the risk assessment phase where the quantitative evaluation of risk at system level was performed including human factor (particularly driver error). The applied methodology adheres to the European Commission Regulation 402/13 on the common safety method for risk evaluation and assessment, and it is in line with the CENELEC standards EN50126 and EN50129 valid for safety-related electronic systems for railway signalling and communication applications.