State Route 1 Pilarcitos Creek Bridge Project in Half Moon Bay

Project Information

The Pilarcitos Creek Bridge on State Route 1 near State Route 92 in Half Moon Bay has been identified as a "scour critical bridge" which requires installation of additional protection for the foundation. Erosion around its supports —known as scour—poses a risk to the structure’s long-term stability, particularly during high-flow events such as floods. Caltrans has initiated a project to restore and protect the bridge.

Construction will require intermittent closures of the right-hand turn ramp from northbound SR-1 to eastbound SR-92. During the construction phase, the bike/pedestrian path running under SR-1 from San Mateo Road to SR-92 will be closed.

Bicycle and Pedestrian Path Detour

Caltrans will close the right-hand turn ramp from northbound SR-1 onto eastbound SR-92 in Half Moon Bay starting on July 7, 2025. Motorists and cyclists may access SR-92 by turning right at the traffic signals. Cyclists and pedestrians using the path are advised to follow the posted detour and take crosswalks across SR-1 to connect back to the path, approximately 500 yards east of the SR-1 – SR-92 intersection.

Map of Bike and Pedestrian Detour Route. From San Mateo Rd, take the crosswalk across SR-1, and then follow SR-92. From the east side of the closure, use crosswalk at Main St and take SR-92 west across SR-1 to path.

Project Schedule

The project will run from summer 2025 through fall 2026. Most construction activities will take place between June and October 2025.

Hours of construction:

Weekdays: 7:00 a.m. to 6:00 p.m.
Saturdays: 8:00 a.m. to 6:00 p.m.
Sundays and holidays 10:00 a.m. to 6:00 p.m.

What is Scour?

Scour is a process in which rapidly flowing water strikes a bridge column resulting in whirlpools that erode the sediment supporting the bridge column, which can compromise the strength of the bridge.

Bridge Scour Diagram

Project Contact

Jeneane Crawford
Public Information Officer - Caltrans District 4
Cell: 510.390.3253
Email: Jeneane.Crawford@dot.ca.gov

Date updated: 6/30/25