State Route 120 Union Road Interchange Improvement Project

Project Facts


The City of Manteca (City), in cooperation with the City of Manteca Redevelopment Agency, the California Department of Transportation (Caltrans), and the San Joaquin Council of Governments (SJCOG), proposes to reconfigure the existing State Route (SR) 120/Union Road interchange to provide sufficient capacity to serve the project design year traffic volumes. A diverging diamond interchange configuration has been selected based on additional engineering analysis and environmental revalidation.

Purpose and Need

The purpose of the SR 120/Union Road interchange project is to:

  • Provide operational and safety improvements to address the anticipated traffic generated from ongoing local development and growth.
  • Enhance circulation and mobility for vehicular traffic, bicycles, and pedestrians including a Class I bikeway.

The City of Manteca has identified within their General Plan the need for improvements to the SR 120/Union Road interchange to service projected growth in employment, residential units, and retail and commercial development on the south side of the SR 120 corridor. The interim signal project at the ramp intersections has temporarily improved the operations of the interchange, however the interchange is operating at unacceptable levels of service in the AM and PM peak hours with drivers experiencing long delays in the near-term.

Additionally, the existing interchange has no sidewalks or bike lanes. SR 120 serves as a significant barrier for north/south access for alternative modes of travel. The Project will include a Class I bikeway at Union Road across SR 120.

Funding Breakdown

The City of Manteca is providing 100% funding for this project, using combination of Redevelopment Funds,  Measure K and other local funds.

Project Schedule

Item Date Actual or Target Date
Project Study Report (M010) 09/03/2007 Actual
Project Approval & Environmental Document (M200) 09/29/2007 Actual
Environmental Revalidation 12/06/2017 Actual
Right of Way Certification (M410) 01/2019 Target
Ready – to – List (M460) 01/2019 Target
Approved Construction Contract (M500) 03/2019 Target
Project Completion (M600) 12/2020 Target

Current Status

  • City Advertised Project on December 10, 2018; Bid Opening Anticipated Jan 30, 2019
  • Caltrans is completing Final PS&E Review and reviewing Utility Documents
  • PG&E has been provided with Notice to Owner to Move 60KV Transmission Line; A Utility Policy Exception was approved on January 14, 2019

Project Contact

Sam Sherman, Project Manager
Caltrans District 10 - Program Project Management
P.O. Box 2048
Stockton, CA 95201-2048
Phone: (209) 948-7889 


Fact Sheet (DOCX)