The Frederick Douglass Memorial Bridge (FDMB) project transforms Washington DC’s South Capitol Street corridor into an iconic, grand, urban boulevard that honors Major Pierre L’Enfant’s 1791 plan for the nation’s capital. As lead designer, we helped replace the declining bridge of the same name with this one-of-a-kind-worldwide, multi-arch structure that links communities along the Anacostia River.
Inventive, elegant design
540-feet in length, this design is as striking as it is technically sophisticated. Its above-deck arch design with cable stay technology allows three sets of lighted, parallel arches to spring high above its deck, cascading to water level along v-piers, visually marking the sky as they cross the river. The system enables the superstructure to freely move through the arches via expansion joints at each bridge end, expanding and contracting through the arches like a glider chair.
Durability and resilience were both critical priorities during the design process. A multi-level corrosion protection system was added to the arch’s structural steel and the rib exterior; the bridge cross section accommodates a reduced, split-use path width for the future inclusion of a 11-foot traffic lane in each direction; and the use of a reliable steel composite deck section, I-shaped plate girders within the edge girders and floorbeams, and precast concrete panels creates a durable structure that eliminates complex inspections. Together, these technical innovations allow the bridge to meet its 100-year service life requirements.
Bridging Communities
For this design-build project, AECOM served as lead designer to the design-build joint venture, South Capitol Bridgebuilders, consisting of Archer Western (The Walsh Group) and Granite Construction Inc. The project’s owner, the District Department of Transportation (DDOT), established a goal of creating an iconic new gateway to the city’s monumental core that reflects the traditions of great civic design in Washington, D.C.
This bridge is just as much a product of innovation as it is of place. Our team sought to embed the project into its surrounding community, with the South Capitol Street Ovals at each bridge end supporting traffic calming while providing an urban oasis with generous landscaped, park-like settings. Extensive regional betterments maximize the corridor’s efficiency, frame public spaces, and connect regional destinations—all integral to neighborhood revitalization and economic development east and west of the river. To directly serve diverse, regional communities, far-reaching, project-related, on-the-job training and mentorship programs were offered.
AECOM’s engineering and consultation approach to honoring L’Enfant’s 1791 original plan provides an outstanding example for engineers evolving landmark urban boulevards while addressing the latest mobility challenges within a socioeconomically diverse region. In addition to garnering praise from Mayor Muriel Bowser and other local leaders, the bridge has received community acclaim—including from the Douglass family.
At its opening ceremony, Frederick Douglass’ direct descendent, Kenneth B. Morris Jr., remarked on the bridge and its revitalizing presence:
“Washington, DC has been a very special place for the Douglass family since Frederick Douglass moved his family here nearly 150 years ago. We are thrilled that this magnificent bridge will educate the public about his legacy, connect DC neighborhoods where he worked and lived, and inspire future generations to agitate for change.”
