A question for the train enthusiasts.

[Roscoe]

my first thought was it would be useful in the stations when there are trains in close proximity, shunting going on, that sort of thing, especially at night, although I imagine the yards are probably well lit up

That very well may be the case, but the point I was making is that the flashing red light is illuminating the rear of the train when it is on the main line kilometres away from any other train and the red light is flashing day and night. 

And yes, the yards have lights on top of tall towers that light up the entire yard.