THE SHORT ANSWER
Caltrans says southbound I-405 in the Sepulveda Pass is reduced to three lanes between Ventura Boulevard and Mulholland Drive from 10 p.m. Friday, September 25 until 5 a.m. Monday, September 28, 2026, for pavement rehabilitation work.
This is a southbound lane reduction, not a full I-405 closure. Caltrans says northbound I-405 mainline lanes are not reduced during this weekend work, although the northbound off-ramp to Getty Center Drive is scheduled to close. The schedule is subject to change because of weather or operational factors.
WHAT IS CLOSED OR REDUCED
During the published weekend window, Caltrans says southbound I-405 is reduced to three lanes between Ventura Boulevard and Mulholland Drive. The Ventura Boulevard on-ramp to southbound I-405 is scheduled to close, along with the southbound I-405 off-ramp to Valley Vista Boulevard/Sepulveda Boulevard and the Valley Vista Boulevard/Sepulveda Boulevard on-ramp to southbound I-405.
Caltrans also lists the northbound I-405 off-ramp to Getty Center Drive as closed during the work. Do not turn that ramp closure into a claim that the northbound mainline is closed.
WHY THIS MATTERS FOR SFV-TO-WESTSIDE TRIPS
The Sepulveda Pass is a major connection between the San Fernando Valley and the Westside. A lane reduction can affect trips to Los Angeles International Airport, the Getty Center area, Westwood, Santa Monica, hotels, events and other destinations, but Caltrans does not publish one universal delay time for every trip.
For any itinerary with a hard arrival time, check the actual origin and destination shortly before departure, build in contingency time and avoid assuming a saved route will remain the fastest option throughout the work window.
DO NOT CONFUSE A LANE REDUCTION WITH A FREEWAY SHUTDOWN
The current Caltrans notice describes southbound lane reductions and specific ramp closures. It does not say all southbound I-405 lanes are closed, all Sepulveda Boulevard routes are closed, or every Westside/SFV connection is unavailable.
Bon Voyage Compass will not describe a hotel, attraction, airport terminal, event, neighborhood or business as inaccessible unless a responsible current source confirms that specific impact.
PROJECT CONTEXT
Caltrans says this work is part of the I-405 Pavement Rehabilitation Project between Van Nuys and Westwood. Travelers should treat the September 25–28 schedule as a time-bounded construction window rather than a permanent traffic pattern.
Because roadway construction can shift, use current Caltrans QuickMap information and posted signs on the travel day instead of relying only on this article.
WHAT BON VOYAGE COMPASS WILL AND WILL NOT CLAIM
Bon Voyage Compass can organize Caltrans's published lane-reduction window, affected ramps and geographic limits into a trip-planning guide. It will not invent a delay time, guarantee a ramp reopening minute, claim northbound I-405 is closed, or infer cancellations or closures for destinations that Caltrans did not identify.
This guide was source-checked September 26, 2026 against Caltrans. It should stop presenting the weekend restriction as active after the published September 28 end time unless Caltrans issues an extension or another current restriction.