What's Happening

The City of San Luis Obispo is preparing for a new US-101 interchange between the Madonna Road and Los Osos Valley Road exits. The Prado Interchange will improve access to Highway 101 with new northbound on and off-ramps, reduce congestion on nearby streets, and support much-needed housing and jobs in south San Luis Obispo. The design work is underway now following City Council direction in February 2025. 

Project Benefits

When completed, the Prado Interchange will connect Dalidio Drive/San Luis Ranch with Prado Road, creating an additional cross-town route that will: 

• Together with the adjacent Prado Creek Bridge Project and the future Prado Road Extension project, will establish a critical east-west connection across the City, enhance emergency response and evacuation capabilities, support infrastructure needs for new housing in the Margarita area, and supports existing housing by linking Prado Road with Dalidio Road and the growing Serra Meadows and San Luis Ranch areas.
• Improve access for residents, businesses, and emergency responders, ensuring a resilient transportation network.
• Alleviate traffic congestion by providing an alternate route to the overburdened Madonna and LOVR interchanges and improve flow on US 101.
• Addresses long-standing traffic congestion and safety concerns identified in regional transportation plans.
• Expand access for drivers, cyclists, pedestrians, and transit users in southern San Luis Obispo

Supporting Broader City Goals

In addition to improving mobility and safety, the Prado Interchange Project supports broader community priorities, including:

• Housing development and access
• Economic vitality
• Climate action and reduced vehicle miles traveled
• A more resilient and connected transportation network

Project News and Updates

Design work has advanced following Council approval on February 18, 2025. Since authorizing the project to move into the Plans, Specifications, and Estimates (PS&E) phase, the team has been refining roadway and bridge designs, coordinating closely with Caltrans, and implementing Value Analysis (VA) recommendations to reduce costs while meeting safety, accessibility, and floodplain requirements. 

On November 4, 2025, Council approved the results of the project's Value Analysis (VA) study, which identified design refinements and construction efficiencies that could save the City an estimated $20 million. The approved VA package authorizes staff to proceed with cost-saving measures, such as optimized bridge widths and revised structural supports, that maintain safety and multimodal access while reducing overall project costs. 

Key activities now underway:

• Design refinement to modern standards and the preferred Alternative A3. 
• Visual/aesthetic planning for bridges, retaining systems, and landscaping (Caltrans process + City design guidance).
• Utility & Right of Way (ROW) planning to avoid conflicts and prepare for acquisitions/relocations on the PS&E timeline. 
• Traffic operations planning and simulations to confirm operations through 2045 and beyond.
• Environmental commitments, including added bike/ped facilities and habitat/flooplain protections. 
• Supplemental Project Report, that will be reviewed by the City's Active Transportation Committee and considered for approval by City Council in late summer 2026 prior to submission to Caltrans for approval.  The Supplemental Project Report documents the necessary changes to the project to reduce construction cost and increase speed of construction. 

If you would like to learn more about this project, please contact City staff as follows: