Pondering Amtrak's proposed $151 billion Northeast Corridor high-speed rail initiative, I feel a sense of despair. On the one hand, it's totally ridiculous that the idea of spending that much money over 30 years is being dismissed out of hand as unaffordable. The 10-year budgetary cost of the wars in Iraq and Afghanistan (PDF) was $1.414 trillion for projects that are still incomplete and haven't had nearly the kind of concrete benefits to Americans that transportation infrastructure would have. What's more, at today's ultra-low interest rates it would genuinely be quite affordable to take out a 30-year loan and start building.
On the other hand, as an actual proposal for what to do with $151 billion in transportation money, this is borderline insane, mostly serving to solve a not-particularly-severe problem at exorbitant cost.
I strongly recommend this Alon Levy post about a set of drastically cheaper smaller-scale interventions that could get travel time from Boston to Washington down to about four hours for about a tenth the cost of what Amtrak is proposing. One key virtue of that alternative is that it would be cheaper. Another even more important virtue of that alternative is that it might actually get done! Projects of the scale Levy is talking about would be expensive, but genuinely within the fiscal capacity of the local jurisdictions to undertake whether or not trains happen to be in vogue in Congress next year.
But even if you spotted me the extra $135 billion to spend on transportation in the region, I still wouldn't go for the Amtrak plan. Less-than-perfect intercity transportation connections are annoying when you experience them, but ultimately not the biggest deal in the world. Things that could transform people's daily lives—incremental upgrades to commuter rail networks, an extra subway tunnel for the D.C. central business district, improved bus shelters and signage, removal of neighborhood-destroying freeway spurs—are much more important than shuffling people between big cities at best-in-the-world speed. Meanwhile, dreaming of the super-expensive plan is distracting Amtrak from actually investing time in scrounging up the money and interagency cooperation it would need to complete the almost-as-good upgrades Levy is talking about.