Martinez Subdivision

California Zephyr crossing the Benicia–Martinez Bridge over the Carquinez Strait, May 2019

Martinez Subdivision
Roseville Subdivision Roseville Davis Yard Sacramento Valley Railroad SacRT light rail Marconi/Arcade RT Maintenance Facility Swanston American River Fresno Subdivision Sacramento Subdivision Sacramento Northern Railway   SacRT light rail   Sacramento Valley Station Sacramento Southern Railroad I Street Bridge over the Sacramento River West Sacramento SERA Woodland Subdivision   Yolo Causeway over the Yolo Bypass   California Northern Railroad Davis Dixon to the Western Railway Museum Fairfield-Vacaville Suisun-Fairfield California Northern Railroad to Valero Benicia Refinery Benicia Benicia–Martinez Bridge over the Carquinez Strait Solano discontinued 1930 Tracy Subdivision Martinez Port Costa Crockett Davis Point Phillips 66 San Francisco Refinery Hercules planned Rheem Richmond Pacific Railroad BNSF Stockton Subdivision Richmond Bay Area Rapid Transit Richmond Greenway (formerly ATSF) Richmond Pacific Railroad Berkeley Emeryville Emeryville Yard Oakland Intermodal Interurban Electric Railway trestle Oakland-16th Street closed 1994 reroute c. 1997 West Oakland Yards Oakland Seaport Niles Subdivision

The Martinez subdivision is a Union Pacific railway line which runs from Roseville, California to Oakland, California. It is informally referred to as the Cal-P line, after the original California Pacific Railroad, who constructed the line from Sacramento to Suisun and Fairfield. (As such, the nickname may only apply to that segment.) The line is entirely double-tracked including bridges, and features extensive sidings.

Originally built as a more direct route to the San Francisco Bay to compete with the Western Pacific Railroad, the Cal-P segment opened months prior to the First Transcontinental Railroad. California Pacific was taken over by the Central Pacific, which in late 1879 completed the line from Suisun-Fairfield to Oakland via the train ferry Solano from Benicia to Port Costa. The present double-track lift bridge across the Carquinez Strait replaced the train ferry in 1930.

The California Pacific became part of the Southern Pacific Railroad (SP) which in the 1990s merged into the Union Pacific Railroad, the line's current owner.

The Capitol Corridor Joint Powers Authority is planning to construct a third track between Sacramento and Roseville as part of a plan to expand passenger rail operations in the area.

The line hosts several Amtrak passenger routes: the Capitol Corridor, Coast Starlight, and California Zephyr operate 36 trains daily over the Benicia–Martinez Bridge. Union Pacific operates numerous freight trains over the route, and BNSF has trackage rights in some segments.