I Street Bridge Replacement

Mark Thomas is leading the environmental clearance and final design for the replacement of the historic I Street Bridge, a 1911 swing bridge spanning the Sacramento River between Sacramento and West Sacramento. Originally built to carry trains and later adapted for vehicles, the existing bridge is now functionally obsolete, with limited vertical clearance and outdated design, prompting the need for a modern, multi-modal crossing.

Our scope included an alignment study to identify the preferred river crossing location, evaluation of movable bridge options, preparation of environmental technical studies, obtaining CEQA and NEPA clearances, and final design. We coordinated extensively with stakeholders, the public, permitting agencies, and Union Pacific Railroad (UPRR), securing temporary maintenance access from the existing I Street viaduct.

The new bridge will be a “neighborhood-friendly,” movable span designed for low-speed vehicular traffic, with widened sidewalks, bike lanes, and provisions for a future streetcar line. It aims to improve connectivity, reduce traffic delays, enhance riverfront access, and support economic development. The original I Street Bridge will remain in use for rail traffic, but the upper roadway will be removed and closed to vehicles.