The railroad signal light system was developed in the early 1900s near Philadelphia and first implemented in 1915 on a newly electrified Pennsylvania Railroad line to Paoli. Signals control track intersections using simple light sequences to instruct trains when to change tracks and how to proceed safely. The sign is an 18” Round with a ring of 5” yellow-tinted lights that display three light points in a row to indicate certain conditions ahead. The lights must be visible at large distances in day and night and all weather conditions. The three light display was found to be the most clearly readable at large distances.

North Carolina Transportation Museum
Spencer, NC

04.16.25