The benefits of virtual signal modelling
Summary
This case explains how survey data, 3D track data and 3D signals were used to provide a comprehensive data set for signal sighting.
Years of study and analysis of hardware and logic have delivered very reliable signalling equipment. More recent events have highlighted the need to focus on signal location, sighting distances and the way in which signals are interpreted by drivers. This is challenging, as traditional techniques for choosing the positions of signals have become harder to use.
Safety regulations make it difficult for staff to gain access to the track, and increasing traffic means operators wish to minimise disruption. Route learning is difficult because a new layout cannot be driven until it is completed, and even then it may not be possible for a driver to pass along every possible route. The rail industry has thus had to devise new ways of establishing signal sighting, and communicate final designs to train drivers. An approach which has been used on Thameslink Programme uses a 3D computer model of the railway, which can be used to place signals by parametric design rules and then perform objective assessment of sighting, aiding subjective assessment within the real environment.