Sighting Distance Evaluation, Irish Rail

The recognition of sighting distances for signals and level crossings is important for legal compliance. It is important that the measurement of sighting distances is calculated on a regular basis as a part of risk assessment and management policy. Short sighting distances will give very little reaction time to the driver when they are required to slow down or stop the vehicle. Sighting distances are particularly affected by track curvature, vegetation growth and visibility conditions. Traditionally, these are measured using manual approaches that are slow and expensive.

In 2009, Rail Vision surveyed the 850 level crossings within the Irish Rail network using automated forward facing video data obtained from their track recording vehicle. The desktop software provides details of sighting distances for each level crossing, and video clip showing the train approaching the level crossing along with distance to the crossing. Further automated approaches allow vegetation and other obstructions to be marked and reported that impair sighting distances.