Is it an electric train track?
There are some gotchas installing electrical stuff parallel to electrified train tracks, as if the traction return current if not sufficiently controlled can make its way into your ground wiring with unpleasent consequences.
I've never worked directly on this stuff, but when they put a tramway in somewhere I used to live there were all sorts of electrical problems because of traction current getting into the power reticulation,l and the cable TV, and a load of other things...