Overrun risk evaluation and assessment
Overruns can lead to serious accidents, sometimes fatal. Relevant organisations must manage overrun risk. These are organisations responsible for changes to infrastructure, signalling, train schedules, or rolling stock.
All key stakeholders need to understand their roles and responsibilities. They must also collaborate to control the risk effectively. Rail Industry Standard RIS-0386-CCS sets out a process to manage the risk for lines where trains are operating using lineside signalling. Although rare, the risk of a train exceeding its movement authority (MA) can happen on lines where trains are operated using a cab signalling system. RIS-0386-CCS needed updating to include in-cab signalling as well as current good practice for trains using lineside signalling.
RIS-0386-CCS was updated with a clear process for managing the shared risk associated with a train exceeding the limit of MA. These changes were supported by a cross-industry drafting review group with representatives from infrastructure managers, train operating companies, and suppliers.
The updated standard has detailed guidance that helps identify of the causes and consequences of overrun risk, as well as the relevant mitigations. It promotes the need to consider both human factors and systematic factors such as technological, organisational, and environmental factors. The standard now also covers in-cab signalling systems. It has new guidance on human factors and ways to manage low railhead adhesion.
The updated RIS has a clear process to manage the shared risk of trains exceeding their MA. This removes the need for separate procedures. It also helps all stakeholders to use a standard approach.
It improves awareness of the cooperation that is needed to meet the Common Safety Method Risk Evaluation and Assessment regulation.
The revised RIS-0386-CCS is expected to give a total benefit of £952,380 over five years.