A big rig crashed on the southbound Interstate 5 freeway shortly after 6:30 p.m. on Wednesday, blocking traffic just north of Lake Hughes Road.
The container truck reportedly veered to the left and hit the center-divider guard rail, according to Officer Josh Greenguard, California Highway Patrol spokesman.
Because the truck was towing about 50,000 pounds, two lanes were expected to remain closed until it can be removed, according to Greenguard.
Caltrans officials were dispatched to the scene shortly before 6:45 p.m. and will be working to clear the debris. No injuries were immediately reported.