Friday, January 9, 2015

NTSB: LED Signals May Mask Light from Incandescent Signals

National Transportation Safety Board recently issued an alert regarding the interaction between light-emitting diode (LED) rail signals and incandescent signals.

Per the release, in certain circumstances “if LED and incandescent signals are installed in proximity to one another, the LED signal may appear brighter or closer, causing crews to confuse the sequence of the signals as they approach. This effect may be more pronounced the closer the train gets to the signals.”

To mitigate this issue, NTSB suggests identifying locations where the issue may occur and conducting a hazard analysis that includes testing signal visibility with input from train crews. Railroads should also evaluate computer aided dispatching (CAD) software.

Additional recommendations can be found on the NTSB alert.