We need the P42's for use on horseshoe curve because Amtrak's Pennsylvanian runs through the line in real life. We just need the P42's and viewliner baggage cars on the line.
I agree we need it for the horseshoe curve route. I went there a bit ago, and I saw an Amtrak P42DC number 86 AND IN GAME: they have Amtrak Altoona Station and Johnstown Station