Major 405 Freeway Closures Start Friday

The 405 is getting squeezed again — and this time it starts tonight, Friday, May 1. Caltrans is cutting northbound Interstate 405 to three lanes through the Sepulveda Pass for the whole weekend, which is about as close as Los Angeles gets to a traffic warning siren. The stretch is one of the main connectors between the Westside and the San Fernando Valley, so even a “partial” closure can ripple far beyond the freeway itself. The news here is simple: a closure that had been delayed by weather is now on, and drivers should expect the usual backup to get ugly fast. (dot.ca.gov) ### Where is the closure exactly? The reduced-lane zone is on northbound I-405 between Getty Center Drive and Ventura Boulevard in the Sepulveda Pass. That is the chokepoint — the hilly section where the freeway narrows into one of the region’s most important north-south corridors. Caltrans says the lane reduction begins at 10 p.m. Friday, May 1, and lasts until 5 a.m. Monday, May 4. (dot.ca.gov) ### How bad is “reduced lanes”? It means northbound traffic drops to three lanes for the extended weekend. That matters because the 405 normally carries huge volumes even when nothing unusual is happening. A cut like that does not just slow freeway drivers — it spills onto Sepulveda Boulevard, surface streets near Brentwood and Sherman Oaks, and the usual escape routes people try once Google Maps turns dark red. (dot.ca.gov) ### Which ramps are closing too? The lane reduction comes with ramp shutdowns in the same area, though Caltrans warns the exact list can shift for weather or operations. The broader point is that this is not just “stay in your lane and inch through it.” Some entry and exit options around the pass will disappear duri(dot.ca.gov)live conditions because the closure setup can change. (dot.ca.gov) ### Why is Caltrans doing this now? This is part of the I-405 Pavement Rehabilitation Project, a $143.7 million job between Van Nuys and Westwood. Crews are replacing damaged pavement, rehabbing other lanes, and trying to extend the life of nearly 92 lane miles. Basically, it is one of those projects everybody hates while it is happening and complains about if it never gets done. (dot.ca.gov) ### Wasn’t this supposed to happen earlier? Yes — the same extended weekend reduction had been scheduled for April 24 through April 27, but weather pushed it back a week. That matters because some drivers may remember the warning and assume it already happened. It did not. Tonight is the actual start. (go511.com) closures as part of a longer construction campaign, and the project page says major work in the corridor continues through mid-2026. So this weekend is the immediate headache, but not the last one. (dot.ca.gov) (go511.com)is avoid northbound 405 through the pass if you can. If you cannot, go earlier, go later, or use a different corridor entirely. The catch is that everybody else will have the same idea, so “alternate route” does not mean “fast route.” It just means maybe less awful. (dot.ca.gov)2026)) ### Bottom line This is a real weekend closure, not a vague traffic advisory. Northbound 405 through the Sepulveda Pass drops to three lanes from Friday night to early Monday, the work is part of a long repaving project, and the backup risk is serious enough that if your trip is optional, this is a good weekend to skip it. (dot.ca.gov)