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Project title

A statistical review of the RSSB Safety Risk Model (T127)

  • Project number:

  • Topic:

    Safety Policy and Risk Management
  • Status:


Project Summary

Reviewing the statistical basis of the Safety Risk Model (SRM) and analysing how it treats rare events.

Project Abstract

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It has been suggested that the RSSB Safety Risk Model (SRM) may overestimate the absolute level of risk in certain areas. SRM is a mathematical representation of 122 hazardous events that could lead directly to injury or fatality on the mainline railway. This research independently reviewed the statistical basis of SRM (Work Package 1) and then looked at ways of improving the model (Work Package 2). WP1 aimed to understand the origins of the differences between SRM and the analysis of fatality data relating to train collisions and derailments carried out by Professor Evans, then of University College London. WP2 takes three of the methods from WP1 and develops them for application within SRM: pooling data to give better estimates of low frequency events, mathematical techniques for predicting casualties in accidents, and procedures for structured expert judgement. This work has ensured that SRM is able to reflect actual experience and has proposed better ways for handling the statistics of rare events.

Project Reports

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