Yet Another Argument Against a High-Speed Rail Line Connecting Dallas and Houston

Speaking of traffic ... Megan McArdle, former Economist now at The Atlantic, is the latest to take up the issue of a hypothetical high-speed rail line between Dallas and Houston, which ain't on the government's to-do list but oh well it's fun to argue anyway. This morning she more or less makes the same argument many Friends of Unfair Park did when this came up last week: There's no need for such a rail line because there's, ya know, Southwest Airlines, for starters:

Many of the people flying between Dallas and Houston are not actually ending up in those cities; they're going somewhere else, because Dallas is a major hub. When I want to fly up to see my family in upstate New York, I don't take Amtrak to Penn Station and then trek out to LaGuardia, even though I much prefer rail travel to air travel. So high speed rail doesn't readily substitute for air travel unless you have a lot of connections running out of Dallas. ...

During peak times, by my count a flight leaves Dallas for Houston every half hour, the better to allow people to tailor their flights to their schedule and their connections. But most of these flights are tiny regional jets that carry perhaps 60 passengers when full. An Acela, by contrast, carries 300. If every single one of those planes was full, and every single one of the passengers switched to rail, you'd have a peak schedule of once every hour and a half to run the train at 80% capacity. But of course, those planes aren't all full, and not all of the passengers will switch to rail, because as I mentioned above, many of them are connecting to other flights.