I was watching a great classic movie the other night on "Chiller" - a channel on DirectTV
"Duel" - 1971
http://www.imdb.com/title/tt0067023/
Its apparently a made for TV movie, with Dennis Weaver being chased by a road raged and crazed trucker, who was driving a tanker full of "flammables"
There are at least 2 scenes where the Southern Pacific is involved. One is where he is driving down the road, thinks he is ahead of truck but the gates come down an a long SP train with 4 locos passes. While stopped, the truck comes up and is trying to push him into the train.
there are a few other scenes where he is on a mountain road and the train is roughly following the road and seen in the distance.
Another scene is he has pulled off the road at a private road and Xing, and hiding behind a rock in his car, to escape the truck. The truck passes by and he falls asleep in his car (a classic Plymouth Valient). he is awoken to the sound of an air horn, and thinking its the truck he awakes in terror, but its an SP Geep (or SD9) passing by him with a train.
all and all, its a good movie - ive seen it a few times, not the best acting, but a good movie with now classic cars and trucks (and trains!) Gotta love the sound of the Slant 6 in the Plymouth