The $60-million interchange project was designed to combat traffic congestion, boost safety and enable pedestrians and bicyclists to move more freely along Battlefield Parkway in Leesburg.

Fabricated at a former dry dock for World War II ships located near Baltimore, 11 concrete tubes—each 10 times larger than a subway car—were towed 220 miles down the Chesapeake Bay by tugboats to Portsmouth, Va., without incident.