The Orange County Transportation Authority (OCTA) in cooperation with The California Department of Transportation (Caltrans) is widening the San Diego Freeway (I-405) between State Route 73 and Interstate 605. This project will improve 16 miles of freeway, along with the replacement and widening of over 18 bridges. In addition, this project will add the 405 Express Lanes, incorporating the existing carpool lanes and a new lane in each direction.
Please click here for an interactive map.
Please click here for the closure list.
For up-to-date information and construction updates, please visit the 405 Improvement Project Facebook page.
Seal Beach Boulevard Sidewalk Closures for Signal Work
Crews closed the sidewalks at the intersection of Seal Beach Boulevard and Lampson Avenue for permanent traffic signal construction.
Activities include the removal of existing sidewalk ramps, installation of new sidewalk ramps, electrical and foundation work.
Permanent traffic signal construction began Tuesday, June 1, and will continue for approximately two more months, on weekdays.
Daytime work hours are 9 a.m. to 3 p.m.
Seal Beach Boulevard and Lampson will be intermittently reduced to two lanes at the intersection for the duration of the work.
NB I-405 Freeway Closures/Detours for Bolsa Chica Road Bridge Work
*If this activity has not been completed, during the timeframes above, work is anticipated to continue on Monday, June 7 from 11 p.m. to 5:30 a.m.
The 405 Community Outreach Team will provide detailed schedule, closure, and detour information in future alerts.
SB I-405 Freeway Closures/Detours for Bolsa Chica Road Bridge Work
Crews will install pre-cast concrete girders for the Bolsa Chica Road bridge over I-405. The girders are the main horizontal support beams, known as the superstructure, the abutments and center columns.
This work will require SB and NB full freeway, lane and ramp closures.
SB freeway closure is set for as early as 10:30 p.m. Friday, June 4, to 7:30 a.m. Saturday, June 5
Westbound SR-22 On-Ramp Extended Closure/Detour
Crews are set to close the Old Ranch Parkway on-ramp to the WB SR-22 for approximately eight months to realign it as part of the I-405 Improvement Project. Activities include demolition, excavation, grading, drainage and electrical system installation, concrete pours and asphalt paving.
Beginning as early as 10 p.m. Tuesday, April 13, for approximately eight months.
• Daytime work hours are 7 a.m. to 4 p.m.
• Crews may mobilize equipment as early as 6 a.m.
• Nighttime work hours are 9 p.m. to 6 a.m.
Motorists should expect delays and use alternate routes if possible.
Please be advised that this work may be loud. Dates and times are subject to change due to unforeseen operational factors or inclement weather.
Seal Beach Boulevard Median Construction
Crews will begin median removal activities on Seal Beach Boulevard between Lampson Avenue and Old Ranch Parkway. This work will require lane reductions on Seal Beach Blvd continuously for the duration of the work.
The center median will be demolished, removed and reconstructed to allow for the addition of a dual left turn lane from southbound (SB) Seal Beach Blvd. to the northbound (NB) I-405 on-ramp.
Activities include median removal, landscaping/tree removal, excavation, concrete work, backfilling, striping and street/median restoration.
Median work is anticipated to begin as early as 10 p.m. Monday, March 29 for approximately one week on weekdays.
Full southbound (SB) I-405 closure between Seal Beach Boulevard and SR-22
SB I-405 Detour is:
EB SR-22 Detour is:
The closure is set for 11 p.m. Saturday, October 17, to 7 a.m. Sunday, October 18.
NB I-405 off-ramp to Seal Beach Boulevard to close for approximately one month
The NB I-405 off-ramp to Seal Beach Boulevard is scheduled to close for approximately one month. The ramp will be reconstructed as part of the freeway widening.
The ramp is scheduled to close at 5 a.m. Monday, June 29, and reopen July 29.
NB I-405 on-ramp from Seal Beach Boulevard closure
Crews are closing the northbound (NB) I-405 on-ramp from Seal Beach Boulevard during the day to continue pile driving activities for a wall adjacent to the ramp.
The daytime closure is set for 6 a.m. to 1 p.m. Thursday, June 18.
The detour is:
NB I-405 off-ramp to Seal Beach Boulevard
Contractors on behalf of the Orange County Transportation Authority (OCTA) will be conducting drainage work as part of the I-405 Improvement Project. Daytime closures are set for Tuesday, May 5th through Friday, May 8th between 6 a.m. and 4 p.m.