Supporting a growing OC community

Investing in the Future

Traffic along the corridor is expected to grow approximately 35 percent by 2040. Improvements are needed to enhance traffic flow, accommodate growing traffic demand, relieve congestion, and improve overall mobility.

The new 405 Express Lanes, new general-purpose lanes and new local bridges of the I-405 Improvement Project are expected to improve the drive for everyone at all times of day, whether they choose to use the Express Lanes or regular lanes.

For Construction updates Visit the I-405 Improvement Project
Aerial photo of the 405 freeway and the bridge at Ward Street under construction

Project by the Numbers

16 Miles of Freeway
Improved for a quicker, more enjoyable driving experience
18 Bridges
Replaced and improved
11 New Bike Lanes
Added for more cycling routes
11 New Sidewalks
Added for pedestrian accessibility
40,000+ Jobs
Created during the entire life of the project
6 Corridor Cities
Plus the community of Rossmoor collaborating to keep traffic moving during construction


The $2.16 billion OC Go project, Measure M, being constructed in cooperation with Caltrans, will be funded mostly through a combination of local, state and federal funds, with the express lanes portion of the Project paid for by those who choose to pay a toll and use the 405 Express Lanes.

OC go sales tax funds

$1.4 billion

State Funds

$90 million

federal TIFIA

$629 million

Federal Funds

$46 million

Project Partners

The project partners thank the following Organizations and cities for their cooperation and participation in the I-405 Improvement Project.

  • OCTA
  • Caltrans
  • FHWA
  • 40 separate utility owners
  • Orange County Flood Control
  • Union Pacific Railroad
  • Army Corps of Engineers
  • U.S. Navy
  • Emergency service providers such as police and fire
  • Costa Mesa
  • Fountain Valley
  • Westminster
  • Huntington Beach
  • Garden Grove
  • Long Beach
  • Los Alamitos
  • Seal Beach
  • Community of Rossmoor