EARLIER this month, Amtrak, America's government-owned passenger rail corporation, released a plan outlining how it's going to spend $151 billion it doesn't currently have (and has no prospect of receiving anytime soon) to bring true high-speed trains to America's crucial Boston-New York-Washington rail axis. Gulliver has already explained why Amtrak's project is ambitious, expensive, and unlikely. But the more you delve into the details of the plans, the sillier they appear.

Take, for example, Amtrak's proposal to bore a 10-mile rail tunnel underneath Philadelphia. As Steve Stofka, a transport blogger, explains, this proposal would require the most expensive type of tunnel imaginable—"It is freaking expensive to bore a ten-mile-long tunnel through an alluvial floodplain under a highly urbanised area—and to maintain it, since it will reside below the water table," Mr Stofka writes. At $10 billion, he notes that the project would be about three times as expensive per mile as the Gotthard Base Tunnel under the Swiss Alps. And all this is for marginal improvements in speed and access. The tracks around and through Philadelphia aren't, generally, big obstacles to high-speed rail—the tunnels in and around Baltimore, Maryland are. It would be much cheaper to replace Baltimore's terrible tunnels than to build a fancy new one under Philadelphia.

The Philadelphia tunnel, unfortunately, isn't even the worst part of Amtrak's plan. That honour goes to a $7 billion renovation of Washington's Union Station (pictured), which Slate's Matthew Yglesias rightly calls "insane". Amtrak's cost estimate is many times higher than for similar projects in Europe. And as Mr Yglesias notes, it seems that Amtrak doesn't have its priorities straight:

[F]rom the look of Amtrak's proposal in addition to the high unit costs problem, there seems to be an awful lot of emphasis on doing stuff that has no really clear operational benefits. For example, they don't like the fact that right now Union Station's existing platforms have unsightly and inconvenient columns in the middle of them. To get rid of the columns, they need to scrap the 2,000-space parking deck that they're supporting. Then they want to replace the parking deck with a 5,000-space four-level underground garage. That's an awful lot of money to spend on something that has minimal operational value from the standpoint of actually operating a railroad.

There's no doubt that America's big east-coast cities could benefit from access to true high-speed rail. But before it gets the funding necessary to make that happen, Amtrak should put forth a credible, smart proposal that puts the needs of passengers and the public first. I have taken Amtrak trains out of Union Station several hundred times. I've never given more than a moment's thought to the "unsightly and inconvenient" columns on the platforms, but I have noticed how trains crawl through the tunnels in Baltimore and move much more slowly, overall, than similar trains in Europe. Renovating Union Station and replacing its parking garage isn't likely to make Amtrak's trains go any faster. Amtrak needs to get a handle on which kind of projects are worth billions of taxpayer dollars—and which aren't.