There may be a limited place for short airport connectors in large, transit-rich cities like New York City, but many of the projects turn out to be far too expensive for the limited service that they provide. They are often a sort of cargo cult urbanism that seeks to emulate the frills of good transit systems isn’t willing to make the hard decisions necessary to actually build a robust network and allow the density to fill it. In the case of the the Providence airport, lawmakers said they hoped the station would attract international service to the currently domestic-only airport – as if Providence can acquire the amenities of a big city without allowing itself to become one. Airport connectors instead are often little more than highly inefficient subsidies to the airline industry, wealthy frequent fliers, and construction unions – which, now that I think about it, might explain why legislators love them so much.I think that if I was going to take a even more cynical view of these projects, I'd say that these connectors are built because people don't like to take buses. People like taking a train (light or heavy) in a way that they don't like taking a bus. I think that's why the East Corridor light-rail extension/airport connector in Denver (the third place I've lived) will actually be popular. It's not so much a TOD project, but the reverse: building a transit line where there's already (some sprawly) development. In this case, much like the Silver Line in DC, politicians have wisely used people's aversion to taking the bus to the airport as a means of building a public transportation spur that, as a byproduct, helps connect areas in between the airport and the city center that are now currently under-served.
Airport Connectors: Not Market Urbanism
I like to use public transportation to get to the airport, whenever reasonable. In Budapest, to get from downtown to Ferihegy 2 (the airport served by the larger international carriers), you have to get on the Blue Metro, take it to the end of the line at Kobanya-Kispest and then take a bus 200E. In Washington, to get from downtown to Dulles airport, you can take the Orange/Blue Metro line to Rosslyn (or start from L'Enfant plaza) and take the 5A bus. In both cases, you're transferring from a train to a bus. Some cities have airport connectors, which are not buses at all. Market Urbanism thinks that this is a boondoggle: