Award of Merit Highway/Bridge: I-270 at Watkins Mill Road Interchange
Constructed over three years, the $110-million crossing helps reconnect long-separated communities. The bridge incorporates a shared-use path for cyclists and pedestrians and fosters a sense of transition through the use of an ashlar stone form liner finish on all precast and cast-in-place concrete elements to match adjacent neighborhood retaining walls.
The project also used brown coatings for bridge beams, light poles, sign structures and guardrails, blending into I-270’s existing color schemes. Utility relocations included a 48-in. water line, two 16-in. sewer lines and a critical electrical duct bank, all of which were located within an environmentally sensitive floodplain. A temporary access bridge and 500-ft stream relocation supported critical elements early in the schedule, improved constructibility and minimized traffic disruptions. Unusual drainage design elements were used to fit within the project constraints. Jack-and-bore techniques allowed a 30-in. pipe to be installed beneath the highway without the need for traffic closures. The project team simplified construction of various project elements.