The Capitol Crossing Air Rights Development transforms a section of I‑395 in Washington, D.C., into a new three‑block urban district built atop a 2.3‑million‑square‑foot overdeck. STV, serving as general engineering consultant, is designing roadway infrastructure for the new tunnel beneath the development as well as surface streets that reconnect the local grid. The project restores historic connections between F and G streets and between Second and Third streets, helping to stitch together a long‑disconnected part of the nation’s capital.
What challenges did STV address?
Reconstructing a major interstate tunnel while reintroducing city streets above it required detailed analysis of traffic operations, security needs and multimodal mobility. STV had to balance the needs of vehicles, transit, pedestrians and cyclists within a dense urban area that includes federal facilities and high‑security zones. Creating new connections over an active highway corridor also demanded extensive structural and systems engineering.
What solutions did STV deliver?
STV is providing traffic engineering, civil and highway design, tunnel and underground structural engineering and security analysis to support roadway integration within the air‑rights development. The firm designed improvements between E Street and the new tunnel portals to enable the reconnection of F and G streets and worked closely with the District Department of Transportation to refine final concepts. STV’s designs ensure safe operations across all modes, improve circulation downtown and support the development’s long‑term functionality.
How does this project benefit the community?
The project restores critical street connections severed for decades by the freeway trench, expanding mobility for pedestrians, cyclists, transit users and motorists. By reestablishing the urban fabric and supporting mixed-use development, the project enhances economic activity, improves circulation, and strengthens community cohesion in the heart of Washington, D.C.
Key stats and accolades
- Three‑block air rights development
- 2.3‑million‑square‑foot highway deck
- Restoration of F and G streets and Second and Third streets
- Improved multimodal mobility in downtown Washington, D.C.
