Octa's transportation blog

First of 18 Bridge Reconstructions Now Open over I-405

Drivers, pedestrians and cyclists traveling along Slater Avenue in Fountain Valley have an easier commute following the reopening last week of the bridge over the I-405.

The Slater Avenue bridge was fully demolished in September 2018 and reconstructed in less than a year. It is the first of 18 bridges to be built, widened or replaced as part of the I-405 Improvement Project, which is expected to speed up travel times on I-405 between Costa Mesa and the Los Angeles County line, an area traveled by more than 370,000 vehicles a day.

After the Slater reopening, the Bushard Street and Talbert Avenue bridges over I-405 in Fountain Valley were closed for traffic for approximately one year so they can be demolished and reconstructed as part of the project.

The Talbert Avenue bridge will be widened to six lanes from four and bike lanes and sidewalks will be added in both directions. The Bushard Street bridge will continue to have four lanes, along with sidewalks and bike lanes in each direction.

The $1.9 billion 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 both the regular lanes and carpool lanes are heavily congested during rush hour and on weekends. 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.

Construction updates, including the latest closure and detour information, are available on the project’s interactive map at octa.net/405map or on the new project mobile app. To download the free app, search for 405 Improvement in the App Store or Google Play.


Sign up & stay
transportation savvy
Your top resource for:
  • Key News
  • Promotions
  • Events
  • Rideshare & Active
  • Freeway Alerts
  • Transit Info
Browse Topic