featured graphic for I-405 Improvement Project after COVID-19. Logo courtesy of OCTA.

I-405 Improvement Project construction alert: Wednesday, July 27

New Portion of the Westminster Boulevard Bridge Opening Soon

Crews began the second phase of construction of the Westminster bridge in 2021. When the new portion of the bridge opens this summer, it will have new vehicle lanes and sidewalks. Additionally, crews are constructing new traffic signals for the Westminster/Springdale Street and the Westminster/Willow Lane intersections.

The I-405 Improvement Project is excited to deliver an improved bridge to your community!

Please note that the northbound I-405 off-ramp to Willow will be permanently closed as part of the bridge improvements, and crews will continue constructing traffic signals, striping new bike lanes and conducting drainage work in the coming months. The 405 Community Outreach Team will provide updates in future alerts.

Stay tuned for more progress!

Closures and Detours

To view and print a detailed list of closures and detours CLICK HERE

NEW! Northbound (NB) I-405 Closure for Restriping

Crews will restripe lanes on NB I-405 in Fountain Valley to accommodate the reopening of the NB I-405 straight on-ramp from Brookhurst.

This work will require a NB I-405 closure between the NB I-405 off-ramp to Brookhurst and the NB I-405 on-ramp from Warner Avenue.

The closure is anticipated as early as 11 p.m. TONIGHT, July 27, to 5 a.m. Thursday, July 28.

Sign up for project-wide and bridge-specific construction alerts at bit.ly/405-signup.

Southbound (SB) I-405 Closure for Restriping

Crews will restripe lanes on SB I-405 in Costa Mesa between Euclid Street and Harbor Boulevard.

This work will require a SB I-405 closure between the SB I-405 off-ramp to Euclid and the SB I-405 loop on-ramp from Harbor.

The closure is anticipated as early as 11 p.m. Saturday, July 30, to 6 a.m. Sunday, July 31.

Euclid Street Lane Reductions for Pavement Work

Crews will conduct pavement work adjacent to the Euclid Street freeway ramps. This work will require Euclid lane reductions.

Euclid will be reduced to one lane in each directions between Condor Avenue and the SB I-405 on-ramp from Euclid.

The closure is anticipated as early as 10 p.m. Friday, July 29, to 5 a.m. Saturday, July 30.

Local access to businesses will be maintained.

Southbound (SB) I-405 Closures for Brookhurst Street Bridge Falsework Installation

Crews will continue installing falsework for the new portion of the Brookhurst Street bridge over SB I-405.

This work will require SB I-405 closures between the SB I-405 off-ramp to Magnolia Street and the SB I-405 on-ramp from Talbert Avenue.

The closures will be scheduled as early as 11 p.m. to 5 a.m. Monday through Thursday, and 11 p.m. to 6 a.m. on Friday.

SB I-405 will be closed:

  • Wednesday, July 27;
  • Thursday, July 28;
  • Friday, July 29;
  • Tuesday, Aug. 2; and again on
  • Thursday, Aug. 4.

These closures will also be used to pave the SB I-405 Warner on- and off-ramps.

Southbound (SB) I-405 Closures for the New I-405/SR-73 Express Lanes Connector

Crews continue to construct the new I-405/SR-73 Express Lanes Connector.

This requires SB I-405 closures between the SB I-405 off-ramp to Harbor Boulevard and the SB I-405 on-ramp from Fairview Road.

SB I-405 closures are anticipated 11 p.m. to 5 a.m. Monday through Thursday, and 11 p.m. to 6 a.m. on Friday.

  • Thursday, July 28;
  • Monday, Aug. 1;
  • Wednesday, Aug. 3; and again on
  • Friday, Aug. 5.

Southbound (SB) I-405 Closure for Restriping

Crews will restripe lanes on SB I-405 in Huntington Beach between Edinger Avenue and Magnolia Street.

This work will require a SB I-405 closure between the SB I-405 off-ramp to Beach Boulevard/Center Avenue and the SB I-405 on-ramp from Magnolia.

The closure is scheduled for 11 p.m. Saturday, Aug. 6, to 6 a.m. Sunday, Aug. 7.

This article was released by the Orange County Transportation Authority.