The ‘Charles Town Crossing’ (Ranson) was historically operated and maintained by the N&W, who used Union Switch & Signal appliances (as opposed to B&O’s “General Railway Signal” wares. Long story short, these are probably the last surviving examples of US&S ‘Color Position Light’ signals in the USA (so, anywhere? – Washington Union Terminal Co. still had a few). They replaced lower-quadrant semaphore signals here as early as the 1920s