Washington Dulles International Airport Main Terminal APM Station

Dulles, Virginia

At the time, it seemed like the future of airports: passengers at Washington Dulles International Airport would wait for their flights in Mobile Lounges, which transported them from the main terminal to their planes with a minimum of effort. A half-century later, with exponentially more fliers, and concourses growing wings and spokes to accommodate the democratization of air travel, the Mobile Lounge is a well-intentioned relic. So after decades of Dulles becoming more conspicuously obsolete (particularly for an airport serving a national capital) the Metropolitan Washington Airports Authority installed an automated light-rail people mover system. It was easier said than done—the project had to be completed in and around one of the world's busiest airports, tunneling through miles of rock and carving out stations beneath current and future facilities without interfering with Dulles's daily operation. The project resembles a massive puzzle, with sites excavated under and around existing buildings and traffic routes, but the highlight is a 105-foot-wide, 1200-foot-long underground station that supports the weight of the still-in-use Mobile Lounges and other vehicles above it, without a single column. A lattice of cables and concrete beams holds the ceiling in place, while keeping the station itself open, and lit in large part with skylights and other translucent elements.