State Route 239 Project

Online Open House


DECEMBER 17, 2021- FEBRUARY 4, 2022

The comment period for the State Route 239 Notice of Preparation closed on February 4, 2022. All comments that were submitted during the comment period will be considered as we put together our Draft Environmental Document that will summarize our environmental studies in the project area. We thank you for your input and participation!

Welcome to the State Route 239 environmental scoping open house. The purpose of environmental scoping is to identify the environmental topics that the project team should study to assess the potential environmental impacts of a construction project. Public input on this project is critical for ensuring the SR 239 project team’s studies are comprehensive and thorough. Within this website you will be able to review informational materials about this phase of our work.

The proposed State Route 239 Project would provide a new, four-lane highway from State Route 4 at Marsh Creek Road in Contra Costa County to Interstate 580 in Alameda County or Interstate 205 in San Joaquin County. This new state route would ultimately improve the transportation network for an area that has few viable north-south roadway connections in this approximately 17-mile stretch between eastern Contra Costa and the Central Valley.

For language translation or accessibility needs, please do not hesitate to reach out to our project team at (925) 390-3794 or