405 Freeway closures set this week for Magnolia Street bridge work

Work on the new Magnolia Street bridge will require overnight closures of parts of the 405 Freeway through Fountain Valley this week, according to the Orange County Transportation Authority.

Crews will begin removing falsework — temporary framework structures used in construction — for a portion of the bridge late Monday, resulting in closure of the interstate’s southbound lanes between Magnolia and Warner Avenue starting at 11 p.m. Monday, Tuesday and Wednesday and continuing until 5 a.m. the next day. The southbound 405 loop on-ramp from southbound Magnolia and the loop off-ramp to eastbound Warner also will be closed.

The northbound 405 will close between Bushard Street and Magnolia from 11 p.m. Thursday, Friday and Dec. 16 until 5 a.m. the next day. The northbound 405 loop on-ramp from northbound Magnolia also will be closed.

Detours will be in place during the closures.

The Magnolia Street bridge was demolished in stages in December 2018 and January and is being reconstructed in a project scheduled to increase the number of traffic lanes from four to six and add bike lanes and sidewalks in both directions.

The bridge is one of more than 18 that will be replaced, built or reconfigured as part of a $1.9-billion project to widen the 405 between the 73 Freeway in Costa Mesa and the 605 Freeway near Rossmoor. The work also has affected the bridges at Harbor Boulevard and Fairview Road in Costa Mesa, McFadden Avenue in Huntington Beach and Westminster, and Bushard Street and Talbert and Slater avenues in Fountain Valley.

Once the larger project is completed in 2023, both directions of the 16-mile stretch of the freeway will have an additional general-purpose lane and a new “express” toll lane, according to the OCTA. The existing carpool lane in each direction will be converted to an express lane.

For more information, email 405project@octa.net or call (888) 400-8994.

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