Amtrak’s key to long-term success is to think of itself as a regional railroad, specifically, a northeastern railroad, writes Matthew Yglesias for Bloomberg.

The trick is to identify routes that have the highest return on investments. Those would be ones that generate large increases in ridership, reducing dependency on federal subsidies.

A best place for that is a high-speed rail in the Northeast Corridor, where it can still be faster to take the train than to fly.

Vast stretches of the U.S. are empty, but U.S. cities, like Philadelphia, New York, and Boston, are crowded, sprawling with old but strong downtowns, perfect for passenger rail service.

The megalopolis from southern New Hampshire to Northern Virginia has 50 million people living there.

The southern half of the Northeast Corridor, New York to Washington, has the most promising high-speed rail corridors in the world, with plenty of intermediary markets in between.

With a core high-speed network from Washington to Boston, other possibilities open up — a Washington-Richmond route expanded to Philadelphia, New York, and Boston, for example.

Same thing with a high-speed line linking Philadelphia to Pittsburgh.

Read more at Bloomberg about this Amtrak funding proposal.