Dulles Airport Replaces Distinctive Mobile Lounge System with AeroTrain

» System marks airport’s advance into the 21st century, but the terminals aren’t necessarily ready.

When it opened in the early 1960s, Washington Dulles Airport was ahead of its time. Its soaring suspended concrete ceiling designed by Eero Saarinen marked a distinctive entry point for visitors arriving to the nation’s capital. Everything about the airport was constructed with the most modern ideas about air travel, including in terms of transportation to and from airplanes. Instead of having travelers descend steps from airplane doors and then walk into the building, the airport’s “mobile lounges” — buses designed to “mate” with airplanes — transported people directly from a dock on the side of the primary terminal to the airplane’s front stoop, where one could simply stroll into a jet.

Over time, the concept grew outmoded. As security measures increased and the number of commuters expanded, waiting around in the main terminal for the appropriate mobile lounge no longer worked as well, as crowding ensued. Eventually, there were too many jets, and Dulles built midfield concourses designed to handle dozens of jets at a time and allow direct walking transfers between flights. They also included jet bridges, whose direct connection to the terminal offered easier access and operations. The direct convenience initially offered by the lounges became a handicap as congestion on the tarmac between the shuttles and aircraft.

The response of the Metropolitan Washington Airports Authority (MWAA), which runs the facility as well as Reagan National Airport, was to build an airport people mover. It opens for service today after seven years of construction. The 3.8-mile AeroTrain cost $1.5 billion and has four underground stations. Many of the airport’s users can now expect faster commutes between check-in desks and planes.

Dulles’ project has become the standard practice for large airports around the world. In opening its people mover along with a new terminal complex in 1971, Tampa became the first city to pioneer the approach. In recent years, cities as diverse as Dallas, New York, San Francisco, and Minneapolis have opened similar mini-trains, which take advantage of the captive audience at airports to move people about efficiently. They have significantly relieved congestion caused by shuttles between terminals at the airports where they’ve been implemented.

Yet Dulles’ method will leave many of the airport’s users in a state of utter disorientation — and do little to reduce travel times for whole segments of the terminals. The fact that the AeroTrain was clearly designed for a more flight-obsessed era doesn’t help matters much, either, since its provisions for future stations will delay current passengers. It demonstrates some of the limits of an expensive fixed-guideway system even in a controlled airport environment.

Part of Dulles’ problem cannot be solved easily with any transit system. With two midfield concourses, both around 4,000 feet long end-to-end, the airport has a difficult arrangement. By comparison, the midfield concourse of Terminal 1 at Chicago’s O’Hare International is only 1,600 feet long. Dulles could have outfitted itself with people movers running the length of its terminal, something that has been implemented in Detroit, but that would be difficult to accomplish with antiquated terminal buildings. As a result, the AeroTrain simply travels between set points, one on each end of the the first concourse (A and B gates) and one on one end of the second concourse (C gates). Because of limitations in available funds, there will be no AeroTrain access to the other end of the second concourse (D gates), which will continue to welcome mobile lounges, as will international arrivals.

As a result, the AeroTrain, which will offer 29 Mitsubishi Crystal Mover rubber-tired vehicles running every two minutes at peak times, won’t help customers attempting to get from one end of a terminal to another. A huge percentage of customers will continue to have long walks to their gates; the linear nature of an airport terminal contrasts severely with the point-centric orientation of a transit system such as AeroTrain. Other airports hoping to implement similar should aim to limit the length of terminals — an airport station can only be convenient for people who feel comfortable walking to gates with heavy bags.

Even more difficult is the fact that the station designed for C gates is located five hundred feet away from the building itself, accessible only via an underground moving walkway. That’s because AeroTrain was built with Dulles’ future expansion in mind, which would theoretically involve the tearing down of C and D gates (which were supposed to be temporary when first built) and the construction of three new midfield concourses and a new south terminal. If that complex were ever built, it the AeroTrain would be expanded into a 10-mile loop with 10 stations.

The problem for Dulles’ planners is that there is no money for those new facilities, and growth in air traffic has slowed tremendously since the project was first conceived. If high-speed rail proponents get their way, it will slow even more — a trend that should force the airport authority to reevaluate whether it needs to plan for any expansion at all. In that case, the station for the C Gates probably should have been built directly adjacent, rather than several hundred feet away. In this case, there is clearly a downside to thinking too far ahead.

Nonetheless, in some ways Dulles will become a better airport as a result of this large investment. The main terminal AeroTrain station has four underground levels (pictured above) and is as long as the whole building. It is built in a way that prevents conflict between arriving and departing passengers by having them exit vehicles on opposite sides. Meanwhile, security facilities, which have cluttered the historic Saarinen structure, will be moved into newly expanded space underground, not only improving passenger experience, but facilitating movement to the transit system and eventually to gates.

The opening of the AeroTrain coincides with the construction of the Dulles Metro project, which will extend Metrorail service from East Falls Church to the airport and then Loudoun County by 2016. MWAA is also in charge of that program, and it has probably learned some valuable experience about building a major transit system from the construction of AeroTrain.

Image above: Dulles Airport AeroTrain Station, from Metropolitan Washington Airports Authority