United Kingdom: Conspicuity of flashing lights – RAIB report is essential reading

24 Sep

The approach to the crossing in similar conditions at the same time of day on the day after the accident –the view from 62 metres. Source RAIB

The approach to the crossing in similar conditions at the same time of day on the day after the
accident –the view from 62 metres. Source RAIB

The Rail Accident Investigation Branch’s report into the fatal level crossing accident on the Beech Hill automatic half-barrier level crossing, near Finningley on December 4th, 2012 is essential reading as it addresses the conspicuity of flashing lights at level crossings.

The level crossing was owned and maintained by Network Rail and was fitted with a data logger which showed that the crossing was operating normally at the time of the accident, with the barriers down as the car approached. The car driver stated that she did not see that the road traffic light signals (wig-wags) at the level crossing were flashing as she approached and only noticed the lights and barriers when she was very close to the crossing. The weather was sunny at the time of the collision but there had been rain showers earlier and the road surface was wet, leading to glare from the low winter sun.

The RAIB took the tested the lights in an optical laboratory. It was found that they were fitted with 36 W lamps and an obsolete design of red lens unit. Their light output was measured to be well below the specification for lights of this type. Network Rail had no plans in place to replace the light units with brighter ones and had no process to identify that such replacement was necessary.

The RAIB has made four recommendations as follows:
– Infrastructure managers to determine which level crossings are fitted with 36 W lamps and draw up plans for their replacement with LED units
– Infrastructure managers to devise a method of assessing the risk of a bright background and glare preventing wig-wag signals from being seen and propose means of mitigating this
– Infrastructure managers to introduce a new ‘brighter’ type of LED wig-wag for use at sites where sunlight glare has been identified as a problem
– Infrastructure managers to enhance the inspection and maintenance process for wig-wag lamps

This report has relevance to all railways assessing risk at level crossings where low sunlight can cause problems, particularly when incandescent lamps remain in use.

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