State Route 120 and Yosemite Ave Interchange

The City of Lathrop and Caltrans District 10 are collaborating on the State Route 120 and Yosemite Avenue Interchange project, identified by solicitation number 10-1G760. This infrastructure initiative aims to improve the existing tight diamond interchange at Guthmiller Road and Yosemite Avenue and State Route 120 between post miles R0.5 and R1.8. Key physical improvements include reconfiguring the westbound on- and off-ramps to a loop and diagonal configuration, widening the eastbound ramps, and expanding Guthmiller Road to four 12-foot-wide travel lanes. The project also incorporates the installation of traffic signals at ramp terminals, two 6-foot-wide bike lanes, and an 8-foot-wide sidewalk on the east side of Guthmiller Road to enhance traffic operations and connectivity between Lathrop and Manteca. Managed by Caltrans District 10 in Stockton, the project has undergone environmental review under CEQA guidelines, resulting in an Initial Study with a Proposed Mitigated Negative Declaration. This determination indicates that the project will not have a significant effect on the environment. The public comment period for these findings was scheduled from October 5, 2026, to November 4, 2026. The project involves coordination with several trustee agencies, including the California Transportation Commission and the City of Lathrop, with primary environmental oversight provided by Senior Environmental Scientist Laura Cook.