405 Freeway Closures To Snarl Traffic Into 2026: How To Avoid The Worst Of It

LOS ANGELES, CA — A weekend of lane and ramp closures on the 405 Freeway in August led to traffic delays so severe that some Angelenos dubbed it another "carmageddon."

Here's the bad news — it's not over, yet. Similar closures are expected about two weekends a month into mid 2026.

Overnight work has been underway on the 405 Freeway in and near the Sepulveda Pass since June as part of the I-405 Pavement Rehabilitation Project, a $143.7 million project to improve safety and mobility along the freeway and extend the life of its pavement, according to Caltrans.

But the biggest headaches will be from what Caltrans calls Extended Weekend Closures — that's when crews shut down lanes and/or ramps on Friday night and keep them closed until Monday morning.

Motorists traveling in the area got a taste of that last weekend, when lane closures and shuttered ramps at Sunset, Wilshire and Santa Monica boulevards led to what one Reddit poster called "the worst gridlock traffic I've experienced in 32 years here."

The traffic woes weren't limited to the interstate. Motorists reported major delays on surface streets in West LA, an area that's already a pain to navigate on normal days.

Other social media commenters compared the traffic to "carmageddon," when the 405 was shut down between the 10 and 101 freeways for an entire weekend in 2011 and 2012.

Here's what you need to know:

Weekend-long closures will be a regular occurrence for months

"The estimated number of Extended Weekend Lane Reductions where at least three lanes remain open in each direction is planned to be about 25," a Caltrans spokesperson told Patch.

Those weekend-long closures will happen at a pace of about every other week — or twice a month.

In other words, the closures are expected to occur well into 2026.

The exact schedule has not been finalized

Caltrans does not have a finalized schedule for each weekend-long closure.

"Due to weather or operational reasons, the schedule is subject to change including the times and dates, the number of closures and other details," the spokesperson said.

A spokesperson told Patch that announcements for upcoming closures will go out in the weeks and days before.

Drivers can sign up for email notifications from Caltrans about the project here.

Two weekend closures are planned for September

As is the case for all holiday weekends, there will be no closures on Labor Day weekend.

The next closures will occur Sept. 5-8 (details from Caltrans) and Sept. 19-22 (details).