[throwawayDC21]

The problem with trains is that the capital investment and up-front work that is needed becomes a political issue[1]. How do you decide on the route of a new train line? Who pays for the line to be built?

Building railway infrastructure was simpler when there was a lot of open country to build long straight lines through, but building a new line today is much harder with compulsory purchase of land and groups lobbying against it. The process takes a long time too, so elected officials won't see the benefits of backing it at the next election.

I think it is unlikely that US freight will move from road to rail without a significant amount of political and financial pressure.

[1] http://en.wikipedia.org/wiki/High_Speed_2