Interstate 5 Louise Avenue Interchange Improvement
Project Description
This project consists of the design and construction of the Interstate 5 / Louise Ave interchange ultimate improvements. Staff is currently pursuing a Diverging Diamond Interchange (DDI) layout with Caltrans. The DDI will accommodate traffic needs while reducing construction costs and right of way acquisitions. The project phases include Project Approval and Environmental Document (PA&ED), right of way acquisition, Plans, Specifications and Estimate (PS&E) and construction. Due to the large construction cost associated with the ultimate interchange improvements and the need for immediate enhancements in traffic operations, City staff has worked with Caltrans to stage the construction.
Project Benefits
Purpose
The purpose of the proposed project is to reduce congestion, improve traffic operations and accommodate anticipated travel demand due to development approved by the City of Lathrop General Plan. Significant economic growth is projected west of the Interstate 5/Louise A venue/River Islands Parkway interchange. Anticipated traffic volumes far exceed current capacities of the existing interchange due to the area's new development. The Louise Avenue/River Islands Parkway Interchange is an important link to I-5 for the City of Lathrop and the surrounding community. The proposed improvements to the interchange will allow the City to continue with the planned growth. The interchange improvements will also improve traffic operations for commuters traveling into and out of Lathrop. These improvements will enhance the traffic operations for through traffic on I-5 by providing improved on and off-ramps at the interchange. The projected growth in and around Lathrop will put traffic demands on the interchange that can not be met unless improvements are made to the existing interchange. Specifically, the project purpose is to:
- Improve local east-west circulation in Lathrop between State Route 99 and Interstate 5
- Improve access to Interstate 5
- Improve traffic operations at the interchange
- Improve traffic operations at the interchange
Need
The project improvements are needed because Lathrop is projected to face increased traffic demands at the Interstate 5/Louise Avenue/River Islands Parkway Interchange, the increased traffic demands will be the result of planned growth in the area. Traffic will experience delays and extensive queuing due to congestion without these improvements. This, in turn, will bring about inefficient fuel consumption, deteriorating air quality, and unacceptable level of service conditions. Without the proposed interchange improvements, these problems would significantly degrade the operations of the Interstate 5 freeway system.
Current Schedule
Project Study Report (M010)
Pending Update
Project Approval & Environmental Document (M200)
November 2023
Right of Way Certification (M410)
To Be Determined
Ready to List (M460)
To Be Determined
Approved Construction Contract (M500)
To Be Determined
Project Completion (M600)
To Be Determined
Funding Source
Locally Funded
Project Status
The project is currently in PA&ED phase.
Project Cost/Programmed (x$1,000):
Programed Project Cost | Capital $ | Support $ |
---|---|---|
Project Approval & Environmental Document | $400 | |
Plans, Specifications, & Estimates | $ | |
Right of Way | $ | $ |
Construction | $ | $ |
Projected Cost as of December 2023: | Planned $ | Expended $ |
---|---|---|
Project Approval & Environmental Document | $ | $428 |
Plans, Specifications, & Estimates | $ | $ |
Right of Way | $ | $ |
Construction | $ | $ |
Public Information Office

Phone: (209) 948-7977
Email: District10PublicAffairs@dot.ca.gov
Address: P.O. Box 2048, Stockton, CA 95201-2048