AeroTrain is a quick and convenient way to transport passengers from the Main Terminal to the midfield concourses. The nearly four-mile AeroTrain system includes four underground train stations, a vehicle maintenance facility, and a passenger security screening facility built on a new mezzanine level in the Main, with less than two minutes of travel time between stations.
The AeroTrain system is the centerpiece of the Metropolitan Washington Airports Authority's capital development program called D2, Dulles Development. More than $3 billion has been invested in Dulles Airport improvements since 2001 with completed projects including: a new airport traffic control tower, new runway, Concourse B extension, two new parking garages, a moving walkway to Concourse B, and the expansion of the Main Terminal. Work is continuing on the expansion of the International Arrivals Building adjacent to the Main Terminal.