by henry6
What I always found interesting, and important for safety, was that position light and semaphore signals with lights, gave an extra added benefit of being able to see the "message" twice or two ways; color position like the B&O had was even better. But redundency is not in the vocabulary of 21st Century businesses, certainly not in those run by the bottom line rather than safety and service. Still, color lights have been used by more railroads around the world longer than anyother system (save semaphores without lights) with a very high degree of safety. Learning the system is not really hard, either, in that a color or combination of colors make an aspect rather than a straight line. Color signals can be single search light, tri faced search light, or stacked like road traffic signals, and do seem to operate quite well where applied. Look in any book of rules and compare the different "systems" based on each railroads different application. (If the LI people think they will have it rough learning one new system, think of those at NJT who have had to learn the PRR, the N&LB, the CNJ, the LV, the RDG, the Erie, the DL&W, the NYC, the EL, the Conrail, and the NJT systems because there is or has been all those signal programs in effect at the same time at one time or another!)