A FedEx truck caught fire Wednesday on the 5 Freeway in Castaic, prompting the closure of two southbound lanes for roughly four hours, authorities said.
Traffic was backed up nearly 4 miles before the lanes were reopened around 8:20 p.m., according to Caltrans.
Firefighters were seen battling a blaze that engulfed the front of the truck and spread to a nearby hill, just north of Lake Hughes Road.
The brush fire was confined to less than 1 acre as of 4:15 p.m., according to the Los Angeles County Fire Department.
Aerial video from Sky5 showed traffic backed up for miles as firefighters worked to extinguish the fire.
A SigAlert had been issued for the southbound lanes, which were expected to stay closed for at least two hours, according to California Highway Patrol.
Caltrans estimated the two lanes would reopen around 9 p.m., but cleanup crews were able to make swifter progress than expected.
Authorities did not provide information on what started the fire or if anyone was injured.
No further details were immediately available.