N9JIG Hit the nail on the head. Like he said the ones near the crossings control the crossing when the engine comes within the limits of said crossing. Some are radio/DTMF controlled, some have manual control, some are dispatch controlled, but most are just automatic. Railroads today use fiber optics buried next to the right of way so MOW crews and maintainers can access the wiring and controls for various right of way equipment. They have defect detectors, switch controls, signal controls, greaser controls, AEI tag readers for car reading, crossing controls, and even call boxes when the radio breaks, but that rarely ever happens and with cell phones there's very few left...