- Home
- Government
- I-405 Improvement Project
I-405 Improvement Project
Currently, the San Diego Freeway (I-405) is one of the most congested freeways in Orange County, carrying more than 300,000 vehicle trips in some sections each day. By 2040, traffic volumes on the I-405 are expected to increase significantly. The I-405 Improvement Project will increase freeway capacity, improve traffic and interchange operations, and enhance road safety to meet state and federal standards.
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 (SR-73) and Interstate 605 (I-605). The I-405 Improvement Project will improve 16 miles of the I-405 and includes the addition of one regular lane in each direction from Euclid Street to I-605, as well as improvements to freeway entrances, exits and bridges. It will also include the construction of the 405 Express Lanes, which will incorporate the existing carpool lanes and consist of two lanes in each direction from SR-73 to I-605. Solo drivers will pay a toll to use the 405 Express Lanes, but carpoolers will be able to utilize the lanes for free.
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 (SR-73) and Interstate 605 (I-605). The I-405 Improvement Project will improve 16 miles of the I-405 and includes the addition of one regular lane in each direction from Euclid Street to I-605, as well as improvements to freeway entrances, exits and bridges. It will also include the construction of the 405 Express Lanes, which will incorporate the existing carpool lanes and consist of two lanes in each direction from SR-73 to I-605. Solo drivers will pay a toll to use the 405 Express Lanes, but carpoolers will be able to utilize the lanes for free.
I-405 Improvement Project Map
For More Information...
Visit OCTA’s website at www.octa.net/405improvement for up-to-date information about the project and to sign up to receive updates and alerts.
You can also follow the project on the following social media sites:
Facebook facebook.com/405Improvement and on Twitter OCTA Twitter and Instagram at: OCTA Instagram Link
Download the I-405 Improvement Project app which includes quick access to current traffic conditions, closures and detours, along with project updates and links to contact the project team. The app is available as a free download from the Apple and Google Play stores.
Use navigation app Waze when traveling through the area, where our closures and detours are incorporated.
If you have specific questions about the I-405 Improvement Project, you can contact OCTA's I-405 Community Relations division directly by phone at (888) 400-8994 or email at 405project@octa.net.
I-405 Improvement Activity in Fountain Valley - What's Happening Now?
June 1, 2021-June 1, 2023 - 12:00am to 12:00am
- Full Bridge Closure Warner Ave. between freeway ramps
March 14, 2022-April 16, 2022 - 12:00am to 12:00am
- Full Closure SB Brookhurst St. Loop On-Ramp onto SB 405
April 11, 2022-April 12, 2022 - 12:00am to 12:00am
- Full Closure WB Warner Ave. on-ramp onto NB 405
April 11, 2022-April 16, 2022 - 10:00pm to 5:00am
- Full Closure NB Harbor Blvd. loop on-ramp onto NB 405
- Full Closure NB Harbor Blvd. On-Ramp onto SB 405
- Full Closure SB Harbor Blvd. loop on-ramp onto SB 405
- Right Lane closed along NB Brookhurst St. between Talbert Ave. and I-405 Bridge
- Left 2 lanes NB 405 between Edinger Ave. and Warner Ave.
- Left 2 Lanes closed along NB I-405 between Magnolia St. and Edinger Ave.
April 11, 2022-April 16, 2022 - 11:00pm to 5:00am
- Full Closure NB 405 between Warner / Magnolia St. off-ramp and NB Magnolia loop on-ramp
- Road Detours: SB I-405 Warner Ave. Off-Ramp, EB Warner Ave., Brookhurst St.
- Road Detours: SB I-405 Warner Ave. Off-Ramp, EB Warner Ave., Brookhurst St.
- FULL CLOSURE SB I-405 Off-Ramp onto SB Brookhurst St
- FULL CLOSURE SB I-405 Off-Ramp onto SB Brookhurst St
- FULL CLOSURE SB Magnolia St On-Ramp onto SB I-405
- FULL CLOSURE SB Magnolia St On-Ramp onto SB I-405
- FULL CLOSURE SB Magnolia St On-Ramp onto SB I-405
- SB I-405 from Warner Ave to Brookhurst St
- SB I-405 from Warner Ave to Brookhurst St
I-405 Improvement Project Launches Interactive Map
OCTA recently launched a fully interactive, mobile-friendly resource for the I-405 Improvement Project.
Users can click on a location to see when construction is anticipated to start and find details on any current pre-construction activities planned in the area. The newly launched map currently features preliminary construction activities that are happening now.
When construction officially commences in early 2018, users can explore the project area in real time, view both planned improvements and current construction activities for each bridge, as well as, updated closure and detour information.
I-405 Bridge Construction Update
OCTA recently released a preliminary bridge construction map showing when construction is anticipated to start on the bridges affected by the I-405 Improvement Project and which bridges will be closed during construction. (Click on the map to the right to enlarge the image.)
The City of Fountain Valley has seven bridges that will be affected by the widening of the I-405 freeway. Each of these bridges will need to be reconstructed to accommodate the freeway below. The Brookhurst, Slater, Warner and Magnolia bridges will remain open with a reduced number of lanes during construction. However, some bridges will need to be closed completely to traffic during construction, including the Ward, Talbert and Bushard bridges.
I-405 Improvement Project Update - March 2017
The OCTA Board of Directors awarded the I-405 Design-Build contract to OC 405 Partners on November 14, 2016. The Orange County Transportation Authority (OCTA) in partnership with The California Department of Transportation (Caltrans) will start construction on the I-405 Improvement Project in late 2017. The project will include:
- One new regular freeway lane in each direction
- Two 405 Express Lanes in each direction
- 18 bridge replacements
- Interchange reconfigurations
- Merge lane improvements
- New and replaced soundwalls
- New bike lanes and sidewalks on local streets/bridges
How Will the I-405 Improvement Project Impact Fountain Valley?
The I-405 Improvement Project will have a direct impact on traffic in Fountain Valley, both on and off the freeway. During construction, all seven bridge overcrossings in Fountain Valley will be taken down and replaced in a phased approach manner to minimize traffic impacts to the greatest degree possible. The affected bridges are on Ward Street, Talbert Avenue, Brookhurst Street, Slater Avenue, Bushard Street, Warner Avenue and Magnolia Street. Onramps and offramps throughout the City will also be improved. This construction will cause detours and traffic delays. Once construction starts, drivers are encouraged to stay informed so they can use alternate routes and to be patient with construction workers and fellow drivers.
There are no full property acquisitions as part of the project. However, there are some locations along the 16-miles of the project where OCTA will require temporary construction easements or partial acquisitions. If you have questions, please contact Christina Byrne, OCTA's Community Outreach Manager, by calling (714) 560-5717 or emailing 405project@octa.net.