Project Description

The Interstate 405 (I-405) Improvement project from Interstate 5 to Harbor Boulevard is located in the Cities of Irvine, Costa Mesa, and a portion of unincorporated Orange County. The project is proposed to extend life expectancy of pavement, improve safety and efficiency for all modes of travelers and maintenance crews, enhance traffic operation, manage congestion, and provide ability to collect, analyze, and utilize data for systems performance along the I-405 corridor. 

Environmental Lead

Caltrans is the Lead Agency for the National Environmental Policy Act (NEPA), the anticipated environmental determination is a Categorical Exclusion (CE). Caltrans is also the Lead Agency for the California Environmental Quality Act (CEQA). An Initial Study (IS), leading to a Negative Declaration (ND) is anticipated CEQA document. 

Project Cost

Total Project Cost: $172,000,000 

The project is funded through the 2020 State Highway Operation and Protection Program (SHOPP), a component under Senate Bill 1 (Roads repair and Accountability Act of 2017). Project funding is scheduled to be programmed in the 2022/2023 fiscal year. It will include both State and Federal funding

Project Timeline

  • March 15, 2020 Program Project
  • July 2020 Begin Environmental Studies
  • June 21 through July 21 2021 Public Circulation Review Period
  • July 7, 2021 Virtual Public Hearing from 6:30 p.m. to 8:30 p.m.
  • October 2021 through February 2022 (anticipated) Project Approval & Final Environmental Document 
  • September 2022 (anticipated) Project Design
  • March 2024 (anticipated) Begin Construction
  • March 2027 (anticipated) End Construction

What is Available

The Draft Environmental Document is an Initial Study with proposed Negative Declaration (IS/ND). The IS/ND is available for review in-person at:

  • Caltrans District 12 Office, 1750 East 4th Street, Suite 100, Santa Ana, CA 92705, on weekdays from 8:00 a.m. to 5:00 p.m (due to COVID-19, by appointments only please call 657-328-6000).

The IS/ND is also available for review at the following locations during normal business hours. Due to COVID-19, Caltrans suggests checking library hours of operation (may be subject to change).

• Mesa Verde Library, 2969 Mesa Verde Dr. E, Costa Mesa, CA 92626
• University Park Library, 4512 Sandburg Way, Irvine, CA 92612

Where do you come in?

Do you have any comments about processing the project with a Proposed ND and IS? Do you disagree with the findings of our study as set
forth in the Proposed ND, the IS, and Draft Section 4(f ) De Minimis Finding? Would you care to make any other comments on the project?

Public Comment Period: June 21, 2021 to July 21, 2021

Virtual Public Hearing on July 7, 2021 from 6:30 pm to 8:30 pm: http://I-405MultiAssetProject.com

Please submit your comments no later than 5:00 pm, July 21, 2021 via:

  • the online comment form available at http://I-405MultiAssetProject.com
  • or in writing to: Iffat Qamar, PhD, Associate Environmental Planner, Caltrans District 12, Division of
    Environmental Analysis, 1750 East 4th Street, Suite 100, Santa Ana, CA 92705.

The date we will begin accepting comments is June 21, 2021. If there are no major comments, Caltrans will proceed with the project’s design


  1. Draft Environmental Document (IS/ND)
  2. Public Notice
  3. Project Fact Sheet 
  4. Frequently Asked Questions

Stay Connected 

Follow Caltrans District 12 on Twitter and/or Facebook.

Use Quickmap for real time traffic updates. Quickmap can be accessed here or downloaded from the App Store or Google Play Store