I’m basically in agreement with Atrios on the question of intercity rail. One thing I do want to add to the conversation, however, is that better intercity rail connections could free up some valuable airport space.
The DC metro area, for example, is served by three airports. One of them, DCA, is much more centrally located than the other two but it’s also smaller and because it’s centrally located it can’t really be expanded. That airport features six daily flights to Pittsburgh, 245 miles away. There are also four flights per day from Dulles, and three flights per day from BWI. Clearly, there’s a lot of demand for going to Pittsburgh. Were there a high-quality DC-Pittsburg rail connection, many of these air trips would instead be done by train. And were that the case, then airport space—particularly the scarce space at DCA—would be reallocated to flights to destinations that really need a plane to get to. Portland or Los Angeles or Miami or what have you. This isn’t number one on my list of American problems, but it really isn’t ideal to have so much of our airport capacity sucked up by these relatively short trips. There are large classes of travel for which there’s no good alternative to an airplane and in an ideal world the vast majority of flights would be on routes like that.
What’s more, there’s a decent chance that jet fuel is going to become prohibitively expensive at some point in the future and then we’ll really be sorry if we’re stuck relying on planes for 200-400 miles trips.