Santa Maria River Bridge Replacement Project

Project Description 

Caltrans proposes to replace the Santa Maria River Bridge on State Route 1 at the border of San Luis Obispo County and Santa Barbara County, just north of the City of Guadalupe. The existing Santa Maria River Bridge has potential for critical scour issues and has a history of alkali-silica reactivity in the concrete, both of which can compromise the structural integrity of the bridge if left as is. The roadway geometry on the bridge deck also no longer meets current Caltrans standards. Replacing the Santa Maria River Bridge is required to address the multiple concerns found on the existing structure.

A new bridge structure will be built and will be located right next to the existing bridge. The existing bridge will be removed after construction of the new bridge structure is complete. State Route 1 will remain open to traffic during project construction, and temporary traffic control will be implemented during construction.

The new bridge structure would be designed to meet current Caltrans standards that includes, but not limited to: highway design, seismic, safety and hydraulic standards. The project will also involve roadway realignment, vegetation replanting, and utility relocations. 

Project construction is expected to start in the 2022/2023 fiscal year.

Graphic of project location map

Project Benefits

Purpose:  The purpose of the project is to restore the structural integrity of the Santa Maria River Bridge to ensure the serviceability of State Route 1 and to maintain a safe, multimodal continuity between Santa Barbara County and San Luis Obispo County.

Need:  The Santa Maria River Bridge was found to be scour critical and has a history of alkali-silica reactivity as documented in the Bridge Maintenance Fact Sheet. Based on the recommendations of the Bridge Maintenance Fact Sheet, Structure Replacement and Improvement Needs Report, and Bridge Inspection Reports, replacing the Santa Maria River Bridge is required.

Funding Breakdown

The project would be paid for with 2018 State Highway Operation and Protection Program funds.

The project is included in the San Luis Obispo Council of Governments’ approved 2019 Federal Transportation Improvement Program.

The project is also included in the Santa Barbara County Association of Governments’ approved Regional Transportation Plan (2017).

The estimated cost of project construction is approximately $29,727,000, with an estimated escalated cost of approximately $33,261,000.

Proposed Project Schedule

  • Environmental document completed on: 11/25/2020
  • Project Report completed on:  12/09/2020
  • Right of way acquisition to be completed on: 08/15/2022
  • Design to be completed: 11/10/22
  • Advertise: 01/03/2023
  • Construction to begin: 10/03/2023
  • Construction to be completed: 02/11/2027


District 5 Public Information Office
Phone:(805) 549-3111