The closure, spanning roughly 17 miles between Harbor Drive in Oceanside and Basilone Road, begins at 11am and is expected to last until 3pm, paralyzing one of the West Coast’s busiest freeway corridors. The announcement came early Saturday morning from the California Highway Patrol, hours after the Marine Corps confirmed that live munitions would be used in its 250th-anniversary showcase, “Sea to Shore - A Review of Amphibious Strength.”
According to a U.S. Marine Corps statement, the demonstration will feature “integrated Navy and Marine Corps operations across air, land, and sea” - including amphibious vehicles, helicopters, and live artillery fired toward the coastline. The event, held at Red Beach within Camp Pendleton, is meant to celebrate the Corps’ history and highlight its modern amphibious capabilities.
But the decision to fire live rounds over a major interstate has drawn swift backlash from state leaders and transportation officials. Governor Gavin Newsom blasted the closure as a “vanity parade”, accusing the White House of failing to coordinate with California officials or provide safety data in advance.
“Flying live rounds over a busy highway without coordination between state, federal, and local partners isn’t just wrong - it’s dangerous,” Newsom said, calling the move “a profoundly absurd show of force that could put Californians directly in harm’s way.”
The Los Angeles Times reported that the freeway shutdown followed confirmation by military officials early Saturday that artillery would, in fact, pass above the roadway - contradicting earlier statements from the Marine Corps that “no public highways or transportation routes would be closed.” State officials responded by ordering the closure “due to safety concerns,” describing it as an “unprecedented precaution.”
The Los Angeles Times reported that the freeway shutdown followed confirmation by military officials early Saturday that artillery would, in fact, pass above the roadway - contradicting earlier statements from the Marine Corps that “no public highways or transportation routes would be closed.” State officials responded by ordering the closure “due to safety concerns,” describing it as an “unprecedented precaution.”
Caltrans warned of significant delays across Southern California and issued alternate route guidance for drivers:
The high-stakes intersection of politics, spectacle, and public safety caps a volatile week of mixed messaging from federal and state agencies. Earlier in the week, the Marines insisted the I-5 would remain open. But by dawn Saturday, officials confirmed what Governor Newsom and Caltrans had feared all along: that artillery fire would cross the highway’s airspace, making closure unavoidable.
Motorists are urged to avoid the area and monitor quickmap.dot.ca.gov for live traffic updates. Gridlock is already being reported across North County and southern Orange County, with ripple effects expected throughout the day.
As Marines commemorate their 250th year with live fire echoing across the coast, the shutdown of California’s most vital freeway has become both a symbol of military might - and a flashpoint in the growing political divide between Sacramento and Washington.
- In San Diego County, northbound travelers are advised to use State Route 15; west-county commuters can connect via SR-94, SR-52, SR-56, or SR-78.
- In Orange and Los Angeles counties, drivers are urged to take SR-91 between I-15 and I-5, with connections through SR-55 for those heading into or out of Orange County.
- The freeway closure also affects regional rail service, with Amtrak, Metrolink, and Coaster trains suspended or delayed in both directions through Camp Pendleton.
The high-stakes intersection of politics, spectacle, and public safety caps a volatile week of mixed messaging from federal and state agencies. Earlier in the week, the Marines insisted the I-5 would remain open. But by dawn Saturday, officials confirmed what Governor Newsom and Caltrans had feared all along: that artillery fire would cross the highway’s airspace, making closure unavoidable.
Motorists are urged to avoid the area and monitor quickmap.dot.ca.gov for live traffic updates. Gridlock is already being reported across North County and southern Orange County, with ripple effects expected throughout the day.
As Marines commemorate their 250th year with live fire echoing across the coast, the shutdown of California’s most vital freeway has become both a symbol of military might - and a flashpoint in the growing political divide between Sacramento and Washington.
Originally published on October 18, 2025.
