Causal self-evident reactionary delays

When trains on Britain’s railways are delayed by three minutes or more, the causes of these delays are investigated and, where possible, each delay is attributed to a cause category and code, and is allocated to one or more incidents that ultimately caused the delay. Delays fall into two broad categories: direct or primary delays, where a train is delayed directly by an infrastructure or rolling stock failure or some other cause, to which the delay is allocated; and reactionary or secondary delays, where a train is indirectly delayed by another delayed train. The delay attribution (DA) process is time- and resource-consuming, and prone to error, inconsistency and dispute, and would benefit from the automation of the attribution process for those reactionary delays whose causes can be determined directly and unambiguously from the data available from the signalling system, and are thus causally self-evident.

TRG has supported CACI Ltd. on this RSSB-sponsored project, reviewing the current DA process in Britain alongside international research and practice, and conducting industry stakeholder engagement to ascertain the nature of the current DA system, its shortcomings, and opportunities and aspirations for improvement. The findings of the review and consultation processes have been presented to RSSB and the project steering group representing the wider railway industry and provide the basis for ongoing option development. TRG also supported CACI in the process of developing, reviewing and calibrating the automated DA algorithm.