The flexibility of buried metal bridges offers significant advantages over traditional beam bridges in high seismic zones. When high deformations are anticipated during a seismic event, such as for bridges spanning a fault line, the ductility of the corrugated metal cross-section can accommodate significant movement. In this case study, a steel buried bridge of elliptical cross-section with 38-ft span, 29-ft rise, and 2 ft of soil cover depth was to be built as an underpass for vehicular traffic below a ski slope near a fault location with ongoing, deep-seated movement on the order of 0.5 in. per year and an anticipated seismic movement of 3 ft lateral and 1 ft vertical. The design criteria dictated that this should be considered as differential movement across the bridge span. The bridge was analyzed using two-dimensional (2D) soil-structure interaction (SSI) finite element analysis (FEA), considering the nonlinearity of both the soil and the corrugated steel structure. Four-point bending tests of the corrugated steel sections and longitudinal seams were used to establish the moment-curvature backbone curves. The seismic design was based on building code provisions with a targeted structural performance level to protect life safety. An allowable curvature was established from the backbone curves and used to check the curvature due to the combination of the ongoing and seismic movement. This approach allowed for significantly more movement in the structure as compared to the typical force-controlled design method for buried bridges.