Spout Run Bridge

From www.cr.nps.gov:

George Washington Memorial Parkway was an ambitious undertaking. Along with the technical difficulties involved in constructing roadways along the rugged banks of the Potomac, the project required close cooperation between federal, state, and local agencies. The National Park Service assumed overall responsibility, with the BPR again lending its road-building expertise. Funding problems plagued the parkway throughout its development, which continued in fits and starts for almost forty years.

By the late 1940s, the parkway had only been extended as far north as Spout Run. An extra arch was added to Key Bridge to accommodate the parkway drive at Rosslyn. The Spout Run Bridge, completed in 1959 to carry southbound traffic on the main parkway, provides a striking example of the artistic possibilities of modern concrete bridge design.

The northern portions of George Washington Memorial Parkway were mostly built in the 1950s-1960s. The longest section, between Spout Run and Langley, Virginia, was officially opened by President Dwight Eisenhower in 1959.