101 Cordilleras Creek Bridge Replacement Project FAQs

The goal is to replace the existing triple box culvert with a single span bridge, while maintaining connectivity and safety for the public traveling along this stretch of U.S. 101. The replacement bridge will retain a 12-lane configuration with six lanes running in each direction.

The bridge was originally constructed in 1930. Recent inspection showed that the bridge is unfortunately at the end of its service life and needs to be replaced.

Much of the construction work required to complete this project must occur within the channel of the creek. To maintain a safe creek habitat, the work must also be contained to a specific season: June through October. Caltrans has designed a construction process that will be completed in one construction season, rather than three seasons over three years, which will have much less impact on the creek habitat. Caltrans also has coordinated with state and federal wildlife agencies on a design that will widen Cordilleras Creek to enhance hydrology and tidal function of the wetland.

Caltrans plans to utilize the “cut and cover” method paired with an Accelerated Bridge Construction (ABC) process, which allows Caltrans to construct the bridge in one season instead of over three years. The cut and cover method will construct the new single span bridge over the existing culvert boxes and then remove the existing boxes, eliminating the need to shift traffic lanes across the freeway.

Shortening the construction timeline from three seasons over three years to one season has a myriad of benefits. Setting up construction staging only once and without maintenance costs between seasons reduced overall project cost. It will also minimize impacts to the creek environment, increase safety of travelers and construction workers, avoid relocation of tolling equipment, and shorten disruption for local neighborhoods.

Using the cut and cover staging and Accelerated Bridge Construction (ABC) process will shorten the construction schedule from three years to one season but will require one 55-hour-long weekend full freeway closure for each side of the highway (northbound and southbound).

The southbound closure dates are:

• September 29-October 2

The northbound closure dates are:

• October 13-16

Weekend full freeway closures will last from 10:00 PM Friday night to 5:00 AM Monday morning. The agreement with the contractor includes incentives and disincentives for every hour the 55-hour closure is completed early or late, respectively.

The intent is to have traffic use different routes to avoid the project area during the weekend closures, but any traffic that approaches the site will be rerouted between the Holly Street and Whipple Avenue exits onto Industrial Way in Redwood City. Portable Changeable Message Signs (PCMS) will be positioned to inform travelers of alternate routes that run parallel to Route 101. The fixed existing Hwy CMS will be utilized during the closure throughout the Bay Area. Additionally, the Smart Corridor elements along State Route (SR) 82, El Camino Real, will be utilized to maximize passage for the traffic that opts to use SR 82.

Caltrans will utilize local and regional print and broadcast media to notify the public about the work and warn them to expect delays during the weekend closures. Motorists will be advised to avoid travel, allow for additional time if travel cannot be avoided, use alternate routes, and take mass transit.

The project team will coordinate with regional airports to notify passengers, fire departments, first responders, and regional trauma centers.  The team will also notify vendors of the commonly used navigational applications to alter their algorithms to route traffic to other regional routes.

Project updates will be posted online at SM101CordillerasCreekBridge.com.

Local agencies will have the opportunity to identify additional mitigation measures such as removal of parking, signal timing changes, or other measures that involve local streets. Caltrans will coordinate with the organizers of any special events that may coincide with the planned closure dates.