Service operated every 30 to 35 minutes between L'Enfant Plaza station and Washington Dulles International Airport on weekdays, and 60 minutes on weekends.[6] WMATA used 2006 Orion VII CNG (07.501) suburbans numbered 2701–2730 based out of Four Mile Run Division to operate the route. However, other buses can be used on the route if the Orion VII CNGs are running on other routes or going under maintenance. Each bus has suburban seating with overhead luggage racks.
The 5A originally operated under the “North Reston Express Line” in the 1970s before being discontinued in the 1990s being replaced by a combination of Fairfax Connector routes.[7]
Service began on December 4, 2000 to connect service to Dulles International Airport from Downtown Washington, D.C.[8][1][9]
The line is unique for being the only WMATA bus line that runs to Loudoun County, has a connection with any Virginia non-commuter services, and is responsible for providing a regular link between the two services. The original $1.10 one-way fare was seen as a bargain compared with other transportation modes in the area, including Shenandoah Valley Commuter Bus.[6]
In 2014, it was reported that the 5A line was partly responsible for Dulles Airport monthly ridership record.[10] WMATA also provides higher levels of service on the line in special times of need, especially on certain holidays.[11]
On September 10, 2020 as part of its FY2022 proposed budget, WMATA proposed to reduce time frequency on route 5A service in order to reduce costs and low federal funds.[12] Although, WMATA planned to eliminate route 5A and replace it with the Silver Line service on its previous proposals.
In 2010, WMATA started a public planning forum, to create the Silver Line route to run to Dulles Airport.[13] The Silver Line would bring riders access via train to serve in Maryland, Washington D.C. and the northeastern portion of Virginia. This project is under Phase 2 of the Silver Line, as Phase 1 runs up to Wiehle–Reston East station.[14] Construction of Phase 2 started in 2014; it was scheduled to open in 2020.[15] Metro officials then announced that the second phase may not be ready for service until about September 2020.[16] Metro later re-evaluated the timetable for the second phase's launch and anticipates it would be ready for service on April 1, 2021, after the agency determines a budget for the 2020–2021 fiscal year (and having taken the impact of the COVID-19 pandemic).[17] Opening of Phase 2 was further delayed for July 2021 and later November 2022.[3]
Since November 15, 2022, Washington Dulles International Airport has on its own Metro station, as the station was built as part of Phase 2 of the Silver Line project. The station was originally planned to be underground,[18] but the plans call for an above-ground station, which will be located next to daily parking garage 1 of the airport.[19] The station is connected to the terminal building using the then-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 Dulles International Airport Metro station opened on November 15, 2022 and replaced the 5A on November 16.[4][20][3][2]
