Tue. Jun 6th, 2023

$1.9 Billion I-405 Improvement Project Kicks Off

The largest highway project under construction in the state to deliver relief on busiest stretch of highway in the nation

The Orange County Transportation Authority, in cooperation with Caltrans, is leading the I-405 Improvement Project between State Route 73 in Costa Mesa and Interstate 605 at the Orange County border with Los Angeles County.
The $1.9 billion project, funded with a combination of local, state and federal funds, will be the largest highway project under construction in California.

The project is adding one regular lane in each direction of the I-405 between Costa Mesa and I-605, as promised to voters through Measure M, Orange County’s half-cent sales tax for transportation improvements. The project is also adding a second lane in each direction that combined with the existing carpool lanes will create the 405 Express Lanes.

WHEN: 9 a.m. Friday, Jan. 26

WHERE: IKEA parking lot, 1475 S. Coast Drive, Costa Mesa, CA 92626


Scheduled speakers include:

  • U.S. Representative Lou Correa
  • U.S. Representative Mimi Walters
  • Assemblyman Jim Frazier, chairman of the Assembly Transportation Committee
  • Assemblyman Tom Daly
  • OCTA Chair Lisa Bartlett, also the Fifth District Supervisor
  • Grover Burthey, Deputy Assistant Secretary USDOT
  • Vince Mammano, Division Director, FHWA CA Division
  • Caltrans Director Malcolm Dougherty
  • OCTA CEO Darrell Johnson
  • Tony Bagheri, Regional Director-Executive V.P. Western USA, OHL USA.


I-405 is the most heavily traveled freeway in the nation, with roughly 377,000 daily vehicle trips near the county line. Traffic is only going to continue growing, with a 30 percent increase expected by 2040.
Set to open in 2023, improvements will reduce travel times for all drivers on I-405. Without the project, by 2040 it would take more than two hours to travel this 16-mile stretch, but with the improvements travel times will be reduced to about 30 minutes in the regular lanes and about 15 minutes if a driver chooses to take the 405 Express Lanes.

During morning and afternoon rush hours, it now takes approximately an hour to get between Costa Mesa and the L.A. County line, a trip that takes about 15 minutes with free-flowing traffic.

By Editor

The New Santa Ana blog has been covering news, events and politics in Santa Ana since 2009.

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