Responding to Paul Krugman’s train-sceptical commenters, Matthew Yglesias points out that high-speed rail in the northeast corridor would benefit coast-to-coast air travelers by freeing up more runways for routes that can’t be traveled by train. You can’t take a train from New York to Los Angeles, so we should upgrade train service from New York to Boston in order to reduce the need for New York-Boston air travel and free up runways at La Guardia (and planes, and jet fuel) for the LGA-LAX route. Then, on a realist note, he adds:

Now a separate question is whether there’s any feasible way to actually do this in a country that doesn’t have a French (or Chinese) level of central political authority empowered to build straight tracks through people’s suburban backyards. The answer seems to be ‘no,