Drivers on both sides of the Santa Monica Mountains will experience delays and disruptions in coming weeks as multiple projects close lanes on Pacific Coast Highway (PCH) and the 405.
Caltrans has announced single-lane closures will continue on PCH between Topanga Canyon Boulevard and Las Flores Canyon Road through late September as recovery work from the Palisades Fire and winter storms progresses.
The ongoing closures allow the U.S. Army Corps of Engineers and utility crews to complete critical infrastructure work during daytime hours and weekends. The Army Corps is clearing properties on a stretch of PCH south of Las Flores Canyon Road through Aug. 3, while Southern California Edison began two months of work this week between Topanga Canyon Boulevard and Big Rock Drive.
For worker and public safety, southbound PCH will be reduced to one lane between 9 a.m. and 5 p.m. on weekdays at both locations. Northbound PCH will face similar restrictions from 5 a.m. to 3 p.m. weekdays between Topanga Canyon Boulevard and Big Rock Drive, and 7 a.m. to 3 p.m. weekdays south of Las Flores Canyon Road.
Weekend travelers face additional disruptions, with the stretch south of Las Flores Canyon reduced to one lane in both directions from 5 a.m. to 5 p.m. for Army Corps work.
The closures are part of extensive recovery efforts after PCH remained shuttered for five months following the Palisades Fire and subsequent winter storms that brought flooding and debris flows to the coastal corridor. The highway section from Santa Monica to Malibu reopened to traffic May 23 but remains an active work zone.
Helicopter Operations May Cause Additional Delays
Drivers should prepare for additional slowdowns this week as Caltrans conducts helicopter operations Wednesday and Thursday to install protective rock mesh on cliffsides about a half-mile north of Big Rock Drive.
The helicopter work, scheduled from 7 a.m. to 5 p.m. both days, will install heavy mesh over a large portion of cliffside above PCH near the former Moonshadows Restaurant at 20356 Pacific Coast Highway. The mesh will serve as a protective system to catch rocks and debris as part of slope restoration work resulting from 2023 winter storm damage.
While no additional lane closures are required for the helicopter project, the aircraft will likely draw attention from motorists and could cause traffic slowdowns. The large helicopter will make multiple trips across the landscape from a lift site to the job site during the installation process.
"Motorists are asked to drive with caution and be alert through the area," Caltrans said in a statement. Crews will post changeable message signs on the highway to alert drivers of the upcoming work.
The helicopter operation aims to complete the slope restoration work quickly. Without aerial assistance, installing the mesh would take ground crews several weeks and require additional lane closures on PCH.
The helicopter's planned flight path will minimize disruption by avoiding traffic lanes and city streets, instead passing over adjacent slopes and cliffsides. Crews conducted door-to-door outreach Monday to alert residents within 500 feet of the flight path, with additional notifications planned for Wednesday and Thursday mornings. All marked buildings must be vacated during operations.
Most buildings near the lift site and flight path remain unoccupied due to recent wildfires.
Caltrans reminds drivers that the speed limit is 25 mph in the PCH work zone area, and traffic fines can be doubled. The agency urges motorists to use caution, slow down and remain alert for workers throughout the active construction zone.
I-405 Weekend Disruptions Begin
Meanwhile, Los Angeles-area commuters will face separate challenges as Caltrans launches extended weekend lane reductions along Interstate 405 through the Sepulveda Pass.
The first closure, originally scheduled for Aug. 8-11, has been rescheduled to run from 10 p.m. Friday, Aug. 22, through 5 a.m. Monday, Aug. 25. The freeway will be reduced to at least three lanes in each direction, with multiple on- and off-ramps closed.
The work is part of the $143.7 million I-405 Pavement Rehabilitation Project between Van Nuys and Westwood. Extended weekend lane closures will occur approximately every two weeks for about 25 weekends, though schedules may change due to weather or operational reasons.
Caltrans strongly encourages motorists to seek alternate routes and explore public transportation options during both the PCH and I-405 construction periods.