Dulles International Airport station

Dulles International Airport is a planned Washington Metro station at Dulles International Airport in Loudoun County, Virginia, U.S., on the Silver Line. Originally planned to be operational by 2018, the station is now expected to open in February 2022. The station was originally planned to be underground, but was built as an above-ground station next to daily parking garage one.
History.
A Washington Metro station had been considered for Dulles since at least 1969, but formal plans were not made until 2002, with the first phase of the project commencing in 2004. According to a 1969–1970 engineering study, a full-scale Metro station was planned (but never built) 28 feet (8.6 m) below a parking lot. The originally planned single-side platform station would not meet current Metro specifications for a center platform, which is necessary since current plans would extend service beyond the airport to western suburbs. Plans for an above-ground facility drew concerns from the Virginia Historic Preservation Office regarding the visual impact on the Eero Saarinen-designed terminal. Consultants estimated that an above-ground station would save $640 million in construction costs.
On April 6, 2011, the Metropolitan Washington Airports Authority (MWAA) board voted 9–4 to build an underground station away from the terminal, rather than an above-ground station away from the terminal, at an additional cost of $330 million. Construction of the underground station would have extended its expected opening to mid-2017. However, on July 20, 2011, the MWAA board reversed its previous vote and approved an above-ground station due to pressure from state and local officials to reduce overall project costs.
Station layout.
The station will be connected to the terminal building using the existing pedestrian tunnel which connects the hourly and daily parking lots and parking garage 1 to the baggage claim level of the airport terminal; it is equipped with moving sidewalks. The section of the tunnel connecting the terminal and daily and hourly lots to parking garage 1 was closed in January 2016 in order to reconfigure that tunnel section to accommodate the future Metro station entrance.