McFadden Avenue bridge reconstruction to bring closures to 405 Freeway, starting Saturday night

It may not have an eye-catching name along the lines of Carmageddon or Jamzilla, but make no mistake: It’s time to start paying close attention to roadwork on the 405 Freeway in Orange County.

That’s especially true now, as work to demolish the McFadden Avenue bridge will require shutting down a section of the freeway part of this weekend and next.

The span over the 405 in Huntington Beach and Westminster closed last week and will be out of service for roughly a year as it is replaced. It’s the first of more than 18 bridges that will be replaced, widened or built as part of a $1.9-billion project to expand a 16-mile portion of the freeway between the 73 Freeway in Costa Mesa and the 605 Freeway near Rossmoor, according to the Orange County Transportation Authority.

To accommodate the demolition, the 405 will be closed in both directions between Beach Boulevard and Bolsa Avenue from about 11 p.m. Saturday to 7 a.m. Sunday the next two weekends, said Chris Boucly, a community outreach manager for the I-405 Improvement project.

Once the freeway is closed, the dirty work begins. Crews will coat the lanes with dirt — perhaps 2 feet deep in some places, Boucly said — to provide a buffer between the roadway and heavy equipment and falling debris.

With that padding in place, workers — some using excavator breakers, which are basically hydraulic hammers — will start chipping away at the concrete bridge. Boucly characterized the process as “contained and controlled,” meaning “no wrecking balls and no explosions.”

Debris will be hauled away for disposal.

Workers will focus first on demolishing the southbound side of the bridge. The other half will be razed the following weekend, prompting another full freeway closure the night of Aug. 25.

While the freeway is shut down, drivers heading north will have to exit at Beach Boulevard, while those traveling south will be detoured at Bolsa Avenue/Goldenwest Street.

Partial nighttime lane closures also are expected during the next two weeks for additional demolition-related activities as needed, according to OCTA.

Once rebuilt, the McFadden Avenue bridge will include two lanes, a sidewalk and a bike lane in each direction. The bridge currently has one lane in each direction and a sidewalk on its north side.

McFadden is one of only a handful of freeway bridges that will have to be closed to traffic during construction. Most — including the Slater Avenue bridge in Fountain Valley, which OCTA also expects to start work on this year — will remain open to some extent.

When the overall 405 project is finished in 2023, both directions of the freeway between the 73 and the 605 will have an additional general-purpose lane and a new “express” toll lane, officials say. The existing carpool lane in both directions will be converted to an express lane.

Though road closures will be necessary as construction continues, OCTA doesn’t seem likely to coin any cheeky traffic-related monikers any time soon.

“We’re simply focused on getting the work done,” Boucly said.

For more information about the project, visit octa.net/405improvement.

luke.money@latimes.com

Twitter @LukeMMoney