A major southern California highway was being shut down while the U.S. Marine Corps stages a demonstration set to involve live fire on Oct. 18, pitting the state’s governor against the federal government yet again.
Interstate 5 will be shut down from Harbor Drive to Basilone Road, a stretch of the main artery over 15 miles, from 11 a.m. to 3 p.m. local time, the California Highway Patrol announced the morning of Oct. 18. The news comes after days of back-and-forth between Gov. Gavin Newsom, federal officials and the Marines over whether the demonstration would require any roads to close.
Vice President JD Vance and Secretary of War Pete Hegseth are scheduled to attend the event at Camp Pendleton, which commemorates the Marines’ 250th anniversary
Parade of Ships celebrates 250th anniversary of US Navy and Marine Corps
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John Owen Scudder, 8 of Philadelphia, waves an American Flag as Scudder stands in the Navy Yard in Philadelphia and views the Parade of Ships, celebrating the 250th anniversary of the founding of the U.S. Navy and Marine Corps, on Thursday, Oct. 9, 2025.
The Marines said in a statement earlier in the week that the event would take place “on approved training ranges and comport with established safety protocols.”
“No public highways or transportation routes will be closed,” the statement said.
Freeway signs warn drivers on Interstate 8 approaching Interstate 5 of “Live Weapons Over Freeway” in San Diego, California on October 18, 2025.
Expect delays by car, rail throughout Southern California, state officials say
An Oct. 18 California Department of Transportation (Caltrans) news release called it an “unscheduled closure.” Interstate 5 will be closed “due to a White House-directed military event at Camp Pendleton involving live ammunition being discharged over the freeway,” Caltrans said.
“Because of the event and closure, drivers should expect delays on Interstate 5 and other state routes throughout Southern California before, during, and after the event,” Caltrans said.
In addition to the coastal freeway, officials said Southern California rail service along the route, which runs from San Diego to Los Angeles, would also be disrupted in the afternoon.
Interstate 5 in California on December 10, 2013, traffic travels north from San Diego to Los Angeles.
But Newsom, calling it an “absurd show of force,” said the morning of the event that the demonstration would include firing “explosive artillery” over the freeway. The shutdown was decided because of “extreme life safety risk and distraction to drivers, including sudden, unexpected, and loud explosions,” Newsom said.
“The President is putting his ego over responsibility with this disregard for public safety. Firing live rounds over a busy highway isn’t just wrong – it’s dangerous,” Newsom said in a statement. “Using our military to intimidate people you disagree with isn’t strength – it’s reckless, it’s disrespectful, and it’s beneath the office he holds. Law and order? This is chaos and confusion.”
Interstate 5 is the primary connection between coastal San Diego County and Orange County. The busy freeway travels directly through the Camp Pendleton Marine Corps base for nearly 20 miles, with no other major thoroughfares in the region.
The Marines told USA TODAY in a statement on Oct. 18 that it did not request the closure.
I-5 in Carlsbad, California, on Oct. 18, 2025
“We appreciate the public’s patience as Marines and Sailors conduct realistic training during today’s historic Amphibious Capabilities Demonstration, showcasing the strength and unity of the Navy-Marine Corps team and ensuring we remain ready to defend the Homeland and our Nation’s interests abroad,” the statement reads.
A Vance spokeswoman pointed to the Marines’ statement when asked for comment.
Newsom said Caltrans received a request from the event organizers to display signage along I-5 that reads “Overhead fire in progress.” State officials also observed live munitions being fired near the freeway on Oct. 17 in an apparent test run, the governor said.
Drivers should expect delays on I-5 and other routes on Oct. 18, the governor’s office said, noting that 65,000 vehicles cross between San Diego and Orange counties each day using the route.
‘No accountability, no planning’
The military news outlet Task and Purpose, citing a Marines statement, reported the artillery exercise was scheduled for 1:30 p.m., which included M777 Howitzer cannons firing from west of the 5 into designated ranges east of the freeway.
Marines fire artillery nearly every week, from High Mobility Air Rocket Systems (HIMARS) to M777 Howitzers, Capt. Gregory Dreibelbis said in an email to USA TODAY. Live-fire training sessions occur regularly at the battery and small-unit levels. At the regimental level, large-scale artillery exercises occur twice per year.
The Marines have used the M777 Howitzer since 2005, Dreibelbis said, adding it’s been “safely and effectively employed” in combat operations, such as in Syria.
“This amphibious demonstration is what Marines and Sailors train for every day,” he said. “Weeks of deliberate planning and rehearsals ensured success at every phase of execution, underscoring the Navy-Marine Corps team’s ability to safely conduct complex amphibious operations.”
Rep. Mike Levin, a California Democrat whose district includes Camp Pendleton, said on social media that public safety and the Marine Corps’ reputation are “far more important than the political agendas of J.D. Vance or Pete Hegseth.
“We can and should celebrate the Marine Corps in a manner that honors their proud legacy without compromising safety or community wellbeing,” he said.
In Oceanside, near the southernmost freeway closure, there was somewhat heavier traffic on the 5, but it didn’t appear to cause issues on city streets, said Assistant Police Chief John McKean.
As he spoke to USA TODAY over the phone, aircraft roared in the background. The Marines’ event included an amphibious assault demonstration. McKean said the freeway hadn’t been shut down before.
“This is just such a public event with the Vice President being here; it got more noted,” McKean said.
On social media, San Diego County Supervisor Jim Desmond, a Republican representing Camp Pendleton and surrounding communities, said the “freeway shutdown shows exactly what’s wrong with politics.”
“No accountability, no planning — just finger-pointing while everyday people sit in traffic, miss work, and watch their plans fall apart,” he said.
(This story was updated to add new information.)
Contributing: Zac Anderson
This article originally appeared on USA TODAY: California closes highway, Newsom cites ‘dangerous’ Marines event