San Luis Obispo City Council Greenlights Redesigned Prado Road Interchange

The City of San Luis Obispo is moving forward with a redesigned version of the Prado Road Interchange project, located between the Madonna Road and Los Osos Valley Road exits on U.S. Highway 101. 

The City Council on November 4, 2025, unanimously approved recommendations from a recent Value Analysis (VA) study for the Prado Road Interchange project. 

Since authorizing the project to advance into the Plans, Specifications, and Estimates (PS&E) stage, the project team has refined roadway and bridge designs, coordinated with Caltrans, and implemented the VA recommendations to minimize costs.  

The project is expected to improve access to Highway 101 with new northbound on and off-ramps and reduce congestion on nearby streets, according to the City’s website.

Once complete, the interchange will connect Dalidio Drive and San Luis Ranch with Prado Road, creating another cross-town route that will: 

• Serve as a multimodal link between Madonna Road and South Higuera Street for drivers, bicyclists, and pedestrians. 
• Support future housing and commercial development in south San Luis Obispo, consistent with the City’s General Plan (San Luis Ranch, Margarita, Tank Farm, and adjacent areas). 
• Reduce congestion on Higuera Street, Madonna Road, and Los Osos Valley Road with the addition of a new US-101 crossing and new northbound ramps.
• Improve safety and emergency response times through better east-west connectivity and traffic signals. 

The new VA study identified design refinements and construction efficiencies that will help save around $20 million. 

The original preferred alternative included four lanes going over US-101. The new VA study proposed reducing the bridge’s width from over 103 feet to around 63 feet. 

The approved VA package allows staff to proceed with affordable measures, such as optimized bridge widths and revised structural supports that ensure safety and multimodal access. 

Design work of the project is in progress, following the City Council’s direction in February 2026, according to the City. 

The project’s design work includes design refinements, aesthetic planning for bridges and landscaping, utility and right of way planning to avoid conflicts, traffic operations planning and simulations, and environmental commitments.

The project design also accommodates California-legal truck traffic, although truck volumes along Prado Road are expected to be low compared to US-101. 

The Prado Road bridge is expected to operate smoothly for 15 years, using 2050 traffic demand numbers. Congestion can occur beyond 2045 if the neighborhood experiences full buildout as per the General Plan. 

Construction is projected to begin in 2029 and end by 2030. 

The Prado Road bridge is part of the overall multimodal corridor improvement initiative, which includes replacing the existing bridge over San Luis Creek, widening roads, and installing utilities and bike lanes.