California High Speed Rail is an 800-mile high-speed rail system currently under construction. It will operate at speeds of up to 220 miles per hour, connecting the Anaheim Regional Transportation Intermodal Center in Anaheim and Union Station in Downtown Los Angeles with the Transbay Transit Center in San Francisco via the Central Valley, providing a one-seat ride between Union Station and San Francisco in 2 hours and 40 minutes. Future extensions are planned to connect to stations to San Diego County via the Inland Empire, and to Sacramento.

Initial infrastructure construction began in the Central Valley, the backbone of the system, in 2012. Construction Package 1 (CP 1) is the first significant construction contract executed on the Initial Operating Section of the high-speed rail program. The CP1 construction area is a 32-mile stretch between Avenue 19 in Madera County to East American Avenue in Fresno County. It includes 12 grade separations, 2 viaducts, 1 tunnel and a major river crossing over the San Joaquin River. The CP 1 design-build contract was awarded to Tutor-Perini / Zachry / Parsons (TPZP), a Joint Venture, after an extensive, multi-year competitive bidding process.

TPZP engaged OPAC to perform engineering design services for the design of 3 overhead bridges that carry local roads across high speed rail tracks in Madera County and the design of a 4000 ft. long trench structure supporting high speed rail tracks. The overhead bridges consist of precast concrete girder superstructures with cast-in-place decks and the trench structure consists of reinforced concrete U-wall sections.