Washington Dulles International Airport of the new C/D concourse has not been scheduled. When built, it is planned that both terminals will be connected to the main terminal and other concourses via the AeroTrain. To that extent, the AeroTrain station at Concourse C was built at the location where the future Concourse C/D structure is proposed to be built, and is connected to the existing Concourse C via an underground walkway. Since many major domestic and international airlines have a large presence at Washington Dulles, there are several airline lounges within the airport: Along with Newark Liberty International Airport, Dulles is one of United
Washington Dulles International Airport mezzanine with more room for lines. A new train system, dubbed AeroTrain and developed by Mitsubishi, began in 2010 to transport passengers between the concourses and the main terminal. The system, which uses rubber tires and travels along a fixed underground guideway, is similar to the people mover systems at Singapore Changi Airport, Hartsfield–Jackson Atlanta International Airport, and Denver International Airport. The train is intended to replace the mobile lounges, which many passengers found crowded and inconvenient. The initial phase includes the main terminal station, a permanent Concourse A station, a permanent Concourse B station, a permanent midfield concourse station