11th Street East Tracy Overhead Bridge Replacement

A Skewed Bridge Design That Minimizes Community Impact and Maximizes Safety
Tracy, California

The 11th Street Bridge is a major thoroughfare in the City of Tracy. The original 11th Street East Tracy Overhead Bridge provided vehicular access over the Union Pacific Railroad tracks, but was too narrow to provide safe access for pedestrians and bicyclists. The bridge design includes a new replacement structure over three active Union Pacific Railroad tracks, wider traffic lanes, eight-foot shoulders which also serve as Class II bicycle lanes, and barrier-separated mixed-use paths that promote safe use across the UPRR tracks by pedestrians and bicyclists.


foot-long highly skewed structure


foot-long girders


foot shoulders

In 2009, we began work on this project and prepared a feasibility study, retrofit strategy report, and type selection report prior to proceeding with the final design. We designed a shorter highly skewed structure in combination with retaining walls and embankment fill at the approaches to span the Union Pacific Railroad mainline tracks.

Located approximately one-half-mile east from Tracy High School, the new 11th Street Bridge features a 291-foot-long highly skewed structure, including mechanically stabilized earth retaining walls and embankment fill at the approaches. The superstructure of the replacement bridge consists of a cast-in-place, post-tensioned concrete box girder. The girders are skewed relative to the centerline of the roadway such that the actual span length of the girders is approximately 200 feet.

The unique skewed bridge girder configuration allowed the superstructure depth to be minimized so that the amount that the residential driveways and adjacent roadway intersections needed to be raised up also could be minimized. The triangular shaped overlook areas that resulted from skewing the bridge girders not only provide aesthetic benefits, but also accommodate a planned aerial intersection for a future extension of MacArthur Drive shown in the city’s general plan without needing to widen the 11th Street Bridge over the railroad tracks. An onsite detour utilizing a prefabricated steel truss bridge was used to minimize the overall construction schedule and reduce safety concerns associated with trying to construct the replacement bridge adjacent to live traffic. The project stimulates sustainable growth and development on the east side of the tracks as it promotes the use of alternative modes of transportation to access downtown Tracy.


2018 Project of the Year Award | Transportation/Bridge Category

APWA Sacramento Chapter

2019 Engineering Excellence Awards | Merit Award in Structural Category

ACEC California


$34.6 million (final construction cost)


  • Engineering


  • Transportation


  • West