The crash was first reported around 1:45 p.m. south of Liberty Canyon Road, according to the California Highway Patrol.
The plane crashed on the far left lane on the northbound side and erupted in flames. The aircraft ended up crumpled up against the center divider.
Los Angeles County Fire Department officials quickly responded to the scene and knocked down the flames.
Fire officials said the pilot, who appeared to be the only person on board, was not injured. Fire officials said no other vehicles were involved in the crash.
ABC7 food coach Lori Corbin was on the freeway and witnessed the crash. She was able to speak with the pilot, who went by his first name Rob. He was off to the side of the wreckage and said his engine failed.
"I picked a spot on the freeway, where I knew there was a big section of cars that weren't there, but the engine completely failed. Fortunately, I was able to not hurt anybody - other than the airplane," he said.
Dramatic video showed the moment the vintage plane crash-landed on the 101 Freeway. The plane was seen flying in low and touch down on the freeway, bouncing up a few times before coming to rest on the center divider.
Both directions of the 101 Freeway were shut down due to the incident. It was unclear when it would reopen as authorities did not provide an estimate.
SIGALERT IN AGOURA HILLS: EB AND WB US-101 AT LIBERTY CANYON RD., ALL LANES ARE CLOSED FOR AN UNKNOWN DURATION DUE TO A COLLISION— CHP PIO - LA County (@CHPsouthern) October 23, 2018
Shortly before 4:30 p.m., one lane on the northbound side reopened. Two lanes on the southbound side opened shortly before 5 p.m.