Not sure if your iPhone will do it in a pinch, but unless you're already very well acquainted with the entire train route, a map of the area could be useful. If the train is stopped somewhere and the passengers are allowed to get off to stretch their legs, you might decide to ask a friend to pick you up at a nearby crossroads or highway exit. You could add certain assets along the train route to the map--motels, supermarkets, malls, alternate public transit, 24-hour restaurants, etc. in case the train will be stuck for a long time.