The Signal Overrun Risk Assessment Tool (SORAT) is an innovative web-based tool designed to quantify, mitigate and manage risk associated with signal overrun risk within UK rail infrastructure. The software’s aim is to improve safety and performance in compliance with Rail Safety and Standards Board (RSSB) requirements. RSK is part of the SORAT steering group, working alongside Network Rail and RSSB to offer technical support on the SORAT process.
Since its launch three years ago, SORAT has been used to complete 13,000 risk assessments and been nominated at the Rail Partnership awards.
SORAT is a powerful risk management tool, incorporating complex mathematical equations into a bespoke design. It is hosted within the national rail environment but is available to both internal and external users. The core functionality of the system is split into three areas: quantitative risk management, qualitative risk management, and management and audit. Quantitative risk management involves using mathematical algorithms to quantify overrun risk on a signal-by-signal basis. Qualitative risk assessment takes higher scoring signals and those with other causes for concern through expert judgement workshops to discuss the risk in more detail and suggest mitigation measures. A full audit trail of decision making is kept, and commissioning processes for handovers and checking and acceptance processes are built in. The SORAT steering group, including RSK, directs the ongoing development of the system.