Apologies for taking up a whole newsletter with a D.C. news story, but I figure we have a lot of D.C.-area readers here, and also this illustrates some general points about mass transit. Here goes.

Last week, the Washington Metropolitan Area Transit Authority (WMATA) announced four proposals for Metrorail expansion, all of which aim to address, among other things, the urgent problem that the system can’t run enough trains to meet non-pandemic ridership on the Orange Line, one of D.C.’s most popular commuting routes. These proposals are just lines on a map without detailed engineering proposals or cost estimates. Presumably, WMATA is also conducting cost-benefit analyses, and it’s possible one will make more financial sense than the others.

But the key flaw in these proposals is that none of them are very good.

The biggest problem is that despite ameliorating the specific Orange Line issue and bringing service to new areas, the plans replicate the flaws that got us to this problem in th…