NTSB issues alert on rail signal visibility

The National Transportation Safety Board (NTSB) recently issued a safety alert that targets the visibility of railroad signals.

Light-emitting diode (LED) rail signals might mask nearby incandescent signals, preventing incandescent signals from being visible to train crews, NTSB officials said in a press release. If LED and incandescent signals are installed in close proximity to one another, the LED signal might appear brighter or closer, potentially confusing crews about the sequence of the signals as a train approaches, according to the alert.

The effect can be more pronounced as a train moves closer to the signals, NTSB officials said.

The alert highlights actions necessary to avoid accidents by identifying locations where the close spacing of signals might cause a signal to either mask or visually dominate another signal, especially at locations where LED and incandescent lights are installed in close proximity.

The actions include evaluating the computer-aided dispatching software to prevent confusion when lining routes non-sequentially at multiple control points; conducting a hazard analysis that includes testing signal visibility with input from train crews; and using configuration management more thoroughly.