Apparently Sunday is my day off. But I would like to consider the following.
"There is another __ Train directly behind this one."
Yes... isn't that , well, sort of the nature of tracks? Where exactly else would another train be? Wouldn't "immediately behind" or "shortly behind" even "really close by" make a bit more sense, even if it is still a horrible and blatant lie? Because that directly behind thing, well, yeah, of course there is. You're not mentioning, maybe, that it's directly behind you fifteen stations back. But given that you're on the same tracks, there's nowhere else it could be.
Personally, I much prefer it when the conductor says something along the lines of, "If you don't fit on this train, get the hell off. We're not going anywhere until the doors close, so I really don't know what you think you're accomplishing by standing there with your ass hanging out." OK, fine, I've never head the conductor say that. But I have heard them get pretty close. And I know it's what they're thinking. I don't blame them one bit. And I truly think it would be far more effective, because nobody is listening to that "directly behind" crap.