More 405 Freeway closures in O.C. expected this week as bridge work continues

A map shows detours scheduled as the Orange County Transportation Authority works to demolish part of a 405 Freeway bridge over the Santa Ana River. Freeway lanes will be intermittently closed overnight weekdays between Euclid Street and Harbor Boulevard the next two weeks.
(Courtesy of Orange County Transportation Authority)

Drivers on the 405 Freeway in Orange County will have more closures to contend with this week — including a complete shutdown overnight Saturday — as work continues on a massive multi-year effort to widen a stretch of the interstate.

Starting as early as Wednesday, lanes on the 405 will be closed intermittently between Euclid Street and Harbor Boulevard so crews can demolish part of a freeway bridge over the Santa Ana River, according to the Orange County Transportation Authority.

Most of that work will take place weeknights between 9 p.m. and 6 a.m. over the next two weeks. Workers also will tear down portions of the bridge structure in the river channel. Euclid will be periodically closed overnight near the bridge.

The work will affect freeway lanes in both directions but will not require a full closure.

The same can’t be said for the scheduled partial demolition of the Bolsa Avenue bridge over the 405 in Westminster. To accommodate that, OCTA will completely close the interstate between Beach Boulevard and Goldenwest Street from roughly 11 p.m. Saturday to 8 a.m. Sunday.

The project was originally set for earlier this month but was postponed after “the construction team encountered some unforeseen conditions on the site that need to be worked on prior to demo,” OCTA spokeswoman Megan Abba said at the time.

The plan is to tear down and reconstruct the bridge in two phases so it can remain open to traffic during construction.

The new span will have seven lanes — two more than it does now — and sidewalks and bicycle lanes in both directions.

Overall, OCTA plans to rebuild 18 bridges as part of a $1.9-billion project to widen 16 miles of the 405 between the 605 Freeway near Rossmoor and the 73 Freeway in Costa Mesa.

Once the expansion is complete in 2023, the freeway will have an additional general-purpose lane and a new “express” toll lane in both directions in the project area. Existing carpool lanes in each direction will be converted to express lanes, according to OCTA.

For additional information about the project and planned closures, visit