Railway undertakings and infrastructure managers should bear the full responsibility for the safety of the system, each for their own part, by continuously controlling the (identified) risks associated to their own activities and when necessary to co-operate with each other for shared interface risks.
New/amended rules shall be traced back to the original identified risk. These new/amended rules are changes and therefore, need to be adequately controlled. They could arise from the monitoring of the safety performance that may highlight new or not previously identified risks. Similarly, it is highly recommended to trace existing rules inherited from the past back to the original identified risk.
Depending on the historical background of the railway undertaking or infrastructure manager, it may appear quite difficult to relate numerous old rules to risks. There is no single solution. Therefore, railway undertakings and infrastructure managers are encouraged to discuss possible solutions (e.g. grouping of rules, cross-references through the definition of processes) and their implementation together with the safety certification body.