The 23‑mile Dulles Corridor Metrorail Project extends the Washington Metropolitan Area Transit Authority (WMATA) Metrorail system from Arlington County to Washington Dulles International Airport and into Loudoun County, Virginia. As part of this major, estimated $6.2 billion investment, STV has been integral to the program’s planning, engineering, cost management, systems development and construction oversight across both phases, helping bring high‑capacity transit service to one of the region’s fastest‑growing corridors.
What challenges did STV address?
The rapidly developing Dulles Corridor – home to Tysons Corner, Reston, Herndon and emerging commercial centers – faced rising congestion and limited transit options. The project also encountered critical early‑stage budget challenges, including Phase 1 preliminary design costs escalating beyond Federal Transit Administration (FTA) expectations, putting New Starts funding at risk. Elevated guideways, tunnel infrastructure, airport access and complex stakeholder coordination further underscored the need for rigorous technical and financial controls.
What solutions did STV deliver?
STV provided cost estimating, systems engineering, structural and facilities design review, and construction oversight for over both phases of the project. In Phase 1, STV rapidly assembled multidisciplinary teams to perform a bottom‑up construction cost evaluation, identifying approximately hundreds of millions of dollars in savings that enabled the project to regain FTA support. STV later served as engineering consultant for Program Management Support Services (PMSS), establishing cost control, change management and digital project systems. Across both phases, services included engineering review, program controls, estimating, scheduling and technical oversight for stations, guideways, tunnels and the Dulles Airport connection.
How does this project benefit the region?
The extension expands WMATA’s reach from the existing Orange Line to Ashburn, delivering high‑quality, high‑capacity transit service that reduces travel times, enhances regional mobility and provides a reliable alternative to automobile use. Phase 1’s opening sparked significant transit-oriented development, while Phase 2 strengthens airport access and unlocks new development potential in Loudoun County. The full corridor extension supports economic growth, sustainability, and long‑term multimodal connectivity across Northern Virginia.
Key stats and accolades
- 23.1 miles of new Metrorail extension across two phases
- 11 miles delivered in Phase 1; 6 stations added in Phase 2, including Dulles Airport station
- $6.2B total estimated program cost
- Supported by FTA New Starts, MWAA, TIFIA loans, and regional toll road funding
- Accelerated community development along both phases, including new mixed-use and commuter facilities
