It’s been quite wonderful to watch huge swaths of the planning community get suckered by the Manhattan Airport Foundation. This prank, which suggests turning Central Park into an airport, won some utterly serious howls of indignation. It also sparked a number of calls to improve access from Manhattan to LaGuardia and JFK.

D.C. is unlike many large cities in that it has a remarkably centrally located airport. It takes a very long time to get to New York’s airports, whether by transit or by car. Los Angeles’ main airport is far from the central city. So is Chicago’s. Here, though, the airport is four subway stops from the CBD and minutes by car.

This has an enormously positive impact on the sustainability of our transportation network. First, it increases the ease of taking transit to the airport. Here in D.C., we can take transit to both Dulles and BWI, but I know that if I could ever get a halfway affordable flight out of National, I’d be super-thrilled simply because it would be easy to get there. From both BWI and Dulles, I always ask around for a ride, though I’m rarely successful. Each flight to National, then, is a few more car trips that don’t get made. It’s also a much shorter car trip, which decreases the VMT considerably (particularly when the taxi monopoly at Dulles is added in).

There’s also the second-order effect of driving development. It is almost universally true that you get a cluster of development around airports. Here’s Dulles:

Here’s O’Hare again:

And here’s Hartsfield in Atlanta:

There is a certain set of businesses that want easy access to air travel and they will locate near the airport. Most of those—particularly the business infrastructure of conference space and hotels—can easily be put in more urban areas rather than out in greenfields and help create vibrant urbanist areas rather than the worst of the suburbs. It’s not a dissimilar argument to the one for high-speed rail. In both cases, you want to put the entrance point for a long-distance form of transportation in the city center, where it can feed a sustainable transportation infrastructure.

Having a centrally located and easily transit-accessible airport, even if it has a sharply limited capacity and is therefore very expensive, is an important and beneficial part of D.C.’s transportation infrastructure. Thank goodness we aren’t in a position where we want to be fooled into thinking they’re turning the mall into an airport.