Interstate 5 and Louise Ave Interchange Improvement Project

The California Department of Transportation District 10 is proposing the Interstate 5 and Louise Avenue Interchange Improvement Project in Lathrop, San Joaquin County. The primary objective of the project is to replace the existing compact diamond interchange from postmile R15.85 to postmile R17.33 with a diverging diamond interchange to support traffic growth outlined in the City of Lathrop General Plan. Comprehensive infrastructure upgrades include widening existing on- and off-ramps, reconstructing the freeway bridge undercrossing, installing ramp metering, and adding new auxiliary lanes under one mile in length. To improve local accessibility and safety, the project will also implement new traffic signals, Class II bicycle lanes, and new sidewalks along Louise Avenue. Managed under solicitation number 10-0E550 with NAICS code 237310, the project has undergone environmental review resulting in a Mitigated Negative Declaration under the California Environmental Quality Act. This determination indicates that the project will not have a significant environmental effect provided that specific mitigation measures, such as those addressing transportation impacts, are implemented. A public review period for the Initial Study and Proposed Mitigated Negative Declaration was scheduled from September 28, 2026, to October 27, 2026. The project is being led by Caltrans District 10 in Stockton, with Laura Cook serving as the primary point of contact.