The bus rolls down the embankment and comes to rest on the train tracks. JNH trots out the old reliable propulsive train cue for the coming bus/train collision.
The Bond scores are a great source of train music.
John Barry's From Russia With Love train music has already been mentioned. I think the exact cue that mimics the speeding up and slowing down of the train is called "The Zagreb Express" on "Bond Back in Action".
I always thought "The Chase Bomb Theme" in Octopussy mimicked the slow chugging of a train entering or leaving a station really well.
In GoldenEye, Eric Serra's "Fatal Weakness" kicks in with its chugging, mechanical propulsion as the armored train speeds up to ram the tank.
In David Arnold's "I'm the Money" (Casino Royale), the opening horn combined with the percussion brings to mind the sense of a train journeying through a lush, expansive landscape (just as seen in the film!).
And the percussion in the opening of Thomas Newman's "The Bloody Shot" (Skyfall) definitely has a consistent sense of propulsion that mimics the charging of the train, which is later replaced by punctuating brass as the percussion fades out.
Ennio Morricone music to L'Ultimo treno della notte (Murder on the Last Train) has a 5 minute track named same as the film title (L'Ultimo treno della notte). This cue has the sound effect of a fast moving train going along the tracks in the background (included purposely by Morricone as part of the music). The music is more suspenseful and slow but certainly interesting when set against the sound of the train going along the track. When you hear it, you know it is Morricone music.
The first thing that came to my mind was the tiny bit in Kong-33 when he demolishes the elevated tracks as the spotlight of the train approaches. Nice white-knuckle set-up.
Don't forget the song "Atchison, Topeka and the Santa Fe" from THE HARVEY GIRLS, which contains other great train music, too. Many MGM musicals had train montages as characters performed across the USA, accompanied by train music interpolating a show tune or several. And I love the orchestral adaptation of "Atchison, Topeka..." accompanying trains in LOONEY TUNES, usually after a character has been struck by one! ??
The three-movement GHOST TRAIN TRIPTYCH by Eric Whitacre.
It's a concert piece for wind symphony, but it is the most train-themed music I think you might ever hear (with the possible exception of the aforementioned "Rock Island" opening song from "The Music Man"). While not a film composer per se (though he has participated in high-level film scoring workshops), Whitacre's music is VERY programmatic and VERY accessible. It shares a lot of DNA with contemporary film music. If you're not already familiar with Whitacre's work, I highly suggest that you start checking him out.
"India Countryside" from that marvelous Victor Fleming. Can't get any more train sweep than what's in that cue. And I'm always a sucker for M. Steiner's ditty just before Kong tears up the el tracks.