In the USA, many train crossings have a small [9x11"] blue sign with an emergency phone number & an ID number for the crossing.
If there's an emergency ~~problem~~ at the crossing, like a stuck vehicle, CALL THAT NUMBER and they will stop any train which would have come to that crossing.
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ETA: ~~apparently the color depends on which railroad owns the crossing~~ that's Canada; in the USA they're all uniform: blue, 9x11", 1" white letters #entertainment