Lathrop City Council
September 8, 2025

LOUISE & I5 INTERCHANGE UPDATE
CITY COUNCIL REGULAR MEETING | SEPTEMBER 8, 2025 | ITEM: 2.5 1 2
VICINITY MAP – PROJECT LOCATION
Roth Rd
Manila Rd
Project
Location
Louise Ave
I-5
Lathrop Rd
Golden Valley
SR-120
3 SITE PLAN
Roth Rd
Manila Rd
NORTH
4 PROJECT MILESTONES
Roth Rd
Manila Rd
Project Milestone Milestone Date
Circulate Draft Project Report
and Draft Environmental
Document
October 2025
Begin Final Design July 2025
Right of Way Certification October 2026
Advertisement February 2027
Begin Construction April 2027
Project Opening Fall 2028
5 PROJECT COSTS
Project Component Preliminary Costs
Project Approval/Environmental Document $687,587
Design (Plans, Specifications, Estimates) $2,789,199
Right of Way Support $198,744
Construction Support $2,825,300
Right of Way Acquisition $1,065,017
Construction $27,187,750
TOTAL PROJECT COST $34,800,000
6 PROJECT CHALLENGES
• Air Quality (Inter-Agency Coordination) – Coordination has been ongoing for Air Quality approval. This required an amendment to the FTIP project description and additional traffic analysis support.
• FHWA Approval – A Modified Access Report is required from FHWA due to the connection to the Federal Interstate system.
• Caltrans Approvals – The interchange will require Caltrans Approval during the Environmental, Right of Way, Design, and Construction phases. • Right of Way Acquisition – Right of way acquisition will be required near the northbound and southbound ramps to accommodate the proposed design. 7 PROJECT BENEFITS
• Operational Improvements – The proposed design will improve the signal operations at Louise Avenue and the interchange on/off-ramps. This will improve the flow of traffic and reduce delays.
• Safety Improvements – The Diverging Daimond Interchange (DDI) reduces vehicle speeds and eliminates conflict points, improving the safety and reducing severity of vehicle crashes.
• Bicycle/Pedestrian Accessibility – The design provides improved bicycle lanes and sidewalks through the interchange connecting the community across Interstate 5. • Compact Project Footprint - The DDI is a compact interchange design that provides improved operations while reducing right of way acquisitions.