The Capital Projects Unit is responsible for the design, contract award and construction support of capital improvement projects programmed in collaboration with OC Road Programs, OC Road Traffic Engineering and OC Operations and Maintenance (O&M). The main task performed by Capital Projects is the design of projects planned or initiated by OC Road Traffic Engineering and OC O&M.

The Capital Projects unit consists of two specialized groups, Road Design and Structure Design. Orange County roadway improvement projects follow roadway geometrics identified within the County's Master Plan of Arterial Highways (MPAH). Additionally, our engineers design projects consistent with the requirements and guidelines contained in the Orange County Highway Design Manual (HDM) and OC Public Works Standard Plans. Our structure design projects include design of new bridges, widening, seismic retrofit, and rehabilitation of existing bridges, as well as retaining wall systems, drainage culverts and roadway approaches to bridges. Design procedures of County structure projects follow the California Department of Transportation's requirements and guidelines.


The Design phase includes engineering studies, and preliminary and final design. Tasks performed during engineering studies include environmental, biological, hydraulics and hydrology studies, traffic considerations, permit requirements, utilities locating and development of alternatives. The final design recommendations and alternatives are documented in a Project Report.

Performance of preliminary design includes determination of right-of-way requirements and preparing draft structure and/or roadway, utility, drainage, traffic, and landscaping plans along with draft specifications, quantities and estimates. To ensure quality control and quality assurance, the project engineer distributes the draft plans, specifications and estimates (PS&E) for peer review by service providers and project proponents at the 65%, 95% and 100%, stages of completion. After each distribution, the peer review comments are addressed and the PS&E is updated. Project design is complete once the final comments are incorporated and the PS&E is ready for final approval by the OC Public Works Director and the Board of Supervisors.


The approved project PS&E is subsequently advertised for bids for approximately 5 weeks before there is a public opening of bids. Once all required documentation has been reviewed and approved, the lowest responsive and responsible bidder is awarded the construction contract. All project participants attend a pre-construction meeting. Project construction will begin once a Notice to Proceed is issued and mobilization activities by the contractor begin. Capital Projects staff assist during this phase of the project development by overseeing project advertisement, and providing support during the construction phase.

Please visit our Projects & Photo Gallery page for more information and photos of some of our active and recently completed projects.