[12] These proposals prompted the Virginia Department of Transportation (VDOT) to evaluate the merits of BRT and heavy rail public transit in the corridor.

[21] On May 15, 2006, Virginia Transportation Secretary Pierce R. Homer announced the creation of an advisory panel headed by the American Society of Civil Engineers.

Gary Baise, the Republican challenger to Gerry Connolly's Fairfax County Board of Supervisors Chairmanship, represented Tysons Tunnel.

[30] Start of construction was delayed as approval of the $900 million federal contribution to project costs awaited the conclusion of FTA's review of the proposal submitted by Virginia.

FTA's concerns included the Metropolitan Washington Airports Authority's inexperience in large design-build contracts, an exaggeration of funding numbers from the Dulles Toll Road and an inability for Metro to maintain the 23-mile (37 km) line once it had been built.

Virginian leaders vowed to address the concerns by January 28, 2008, as several fixed price contracts for building materials costs were due to expire on February 1.

[33] On April 30, 2008, the FTA reversed the earlier decision and approved the above-ground project, saying that it met standards for cost efficiency, construction and ridership, moving it closer to receiving the $900 million in federal funding.

MWAA had fifteen days to review the documentation and decide whether it agreed, but on February 24 they announced that the contractor had failed to meet seven of twelve criteria outlined in the contract.

[48][49] On March 19, 2014, MWAA announced additional delays in the project due to public address speakers and a communications cable that did not meet code and did not offer a new completion date.

[50][55] After a set of speeches and announcements prior to opening, which were televised on local cable television station News Channel 8, and attended by the Governor of Virginia, Terry McAuliffe, Metro General Manager Richard Sarles, the entire Metro board of directors, District of Columbia Mayor Vincent C. Gray, and other regional politicians, a ribbon cutting took place at Wiehle–Reston East, and shortly after noon on July 26, 2014, the five new stations were opened for passenger service.

[61] The addition of the Silver Line creates a three-line overlap from Rosslyn to Stadium–Armory, a fact that led WMATA to publicly announce in 2010 that it was considering a new map design.

[62] A number of unofficial attempts by graphic designers to redraw the Washington Metro map to include the Silver Line have done so by thinning the strokes throughout.

[60][63][64] A poster displaying a map of similar design has been hanging in DC Councilman Jack Evans' office for a number of years, but received scant attention until 2008.

The underground station would be more convenient to travelers, but would come at an additional cost of $330 million and would extend the construction time of the project, delaying the expected opening to mid-2017.

[72] Republican former Virginia Governor Bob McDonnell opposed the decision to build a more expensive underground station and threatened to withhold support for the project.

[93] Towards the end of the year, after considering the pace of the work being done and efforts to address outstanding issues, Metro officials then announced that the second phase may not be ready for service until about September 2020.

[94] During a Metro board meeting in December 2019, officials floated the idea of fully replacing the defective concrete panels provided by the MWAA during construction, instead of just repairing them.

[96] However, by the end of March 2020, while determining a budget for the 2020–2021 fiscal year (and having taken the impact of the COVID-19 pandemic into consideration), Metro re-evaluated the timetable for the second phase's launch and anticipated it would be ready for service on April 1, 2021.

They offered local bus service from Wiehle, Greensboro, Spring Hill, Tysons, McLean, and East Falls Church to Ballston.

Originally, WMATA planned on reducing Orange and Silver Line trains while continuously single tracking at East Falls Church instead of a full closure.

[103] On June 24, 2020, WMATA announced that Silver Line service would resume three weeks early when trains are able to bypass East Falls Church.

[107] In September 2020, the Metro Office of Inspector General (OIG) reported that more cracks were discovered in five of the six new stations on the second phase and wants the concrete panels to be replaced before the WMATA Board accepts responsibility and opens the new extension.

In light of ongoing issues, as well as budget cuts resulting from declining ridership caused by the COVID-19 pandemic, Metro pushed back the opening of the Phase 2 extension first to July 2021,[108][109] and on December 15, 2020, to Fall of 2021.

[110] On December 14, 2020, WMATA announced that Blue Line service would be suspended between February 13 to May 23, 2021, in order to rebuild the platforms at both Arlington Cemetery and Addison Road.

[113] On November 4, 2021, MWAA declared the work on the rail line to be "substantially complete"; however, WMATA estimated that it could take five months of testing and other preparations before passenger service could begin.

[118] However, on March 24, 2022, general manager Paul Wiedefeld announced that the projected opening would be delayed once again and declined to give an estimated date of completion.

[122] On September 22, Metro's board of directors voted unanimously in a meeting to authorize current general manager Randy Clarke to determine the opening date for Phase 2.

The first is to link Washington, D.C. by rail to Dulles International Airport and the Northern Virginia edge cities of Tysons, Reston, Herndon, and Ashburn.

Two elevated stops along the west side of Route 123 serve the national headquarters of Capital One, SAIC and two enclosed Tysons Corner shopping malls.

A storage yard and maintenance facility branches off to the west occupying the airport's buffer zone north of the end of its major runways.