I do actually think there _is_ a case to be made:
1) Environmentally - if there are people commuting then rail is presumably better for the environment than cars.
2) It makes cities more viable, and therefore helps job concentration.
But I also think that a lot of commuter train subsidies basically allow middle class people to live outside of the city at a subsidised cost. I'd rather that that money went to improving the city and making it cheaper and easier for more people to live there in the first place and not commute at all. (tags: trainstransportmoney )