News Story

The I-405 Improvement Project is now more than halfway complete

ORANGE – The Magnolia Street bridge over I-405 opened on Saturday, May 22, marking another major milestone for the I-405 Improvement Project, which is now more than halfway finished.

The Magnolia Street bridge is the fifth to open among 18 being built, widened or replaced as part of the project, but it’s the first to open that was reconstructed one half at a time. This allowed Magnolia Street, which straddles Huntington Beach, Fountain Valley and Westminster, to remain open to traffic during construction, minimizing impacts to the community.

“The new bridge not only benefits the residents and businesses near Magnolia Street, it’s also an important step toward meeting the project’s overall goal of improving the commutes of the thousands of drivers who travel on the 405 each day,” said OCTA Chairman Andrew Do, also the county’s First District Supervisor. “I appreciate everyone’s continued patience during construction and hope that everyone who drives the 405 takes some time to support our local businesses along Magnolia Street.”

The first half of the Magnolia Street bridge was demolished in late 2018 and opened to traffic in spring 2020, after which work began on the second half. The new bridge is wider than the old one, with six traffic lanes instead of four, and sidewalks and bike lanes on both sides of the street.

More information about the bridge is part of a video commemorating its opening, available at https://youtu.be/Afr9aAOWPtk.

Four other bridges on the project have also been completed. Slater Avenue in Fountain Valley was the first bridge to open in 2019. Last year, Bushard Street in Fountain Valley and McFadden Avenue, which links Huntington Beach and Westminster, were completed. And last month, Talbert Avenue in Fountain Valley opened.

In addition to the bridge construction, substantial work to improve on-and off-ramps, widen the freeway and replace soundwalls has been completed. As a result, overall construction on the project that began in early 2018 is approximately 55 percent complete.

Next month, the Warner Avenue bridge in Fountain Valley is expected to fully close to traffic for reconstruction. Demolition of the overcrossing will require overnight closures of I-405 near the bridge.

For the latest construction schedule, as well as closure and detour information, visit the project’s interactive map at octa.net/405map.

The I-405 Improvement Project will add one regular lane in each direction between Euclid Street and I-605, and a second lane in each direction in the center of the freeway from SR-73 to I-605 that will combine with the existing carpool lanes to form the 405 Express Lanes.

This 16-mile segment of I-405 is one of the most heavily traveled stretches of highway in the nation, and drivers routinely face severe congestion in both the regular lanes and carpool lanes. The project is critical to accommodate expected employment, population and housing growth throughout the region.

The speed limit on I-405 has been reduced to 55 mph between SR-73 and I-605 for the safety of drivers and construction crews for the duration of the project, which is expected to be completed in 2023. Drivers are advised to slow down and proceed with caution whenever signs of highway work are present, and drivers whose vehicles become disabled should pull off at the nearest exit, if possible.

For more information about the I-405 Improvement Project, visit octa.net/405improvement.