The accident happened around 5:30 p.m. in the midst of rush hour. A big rig jackknifed after colliding with two other vehicles and spilled fuel onto the roadway. All lanes were shut for two hours.
A carpool lane was opened just before 6:30 p.m. and remaining lanes would be closed until about 7:30 p.m., the California Highway Patrol said. By 8:15 p.m., three lanes were opened to traffic.
One lane remained blocked at Valley Vista and Sepulveda boulevards at 10 p.m. All lanes were reopened at 10:30 p.m.
Some injuries were reported in the accident. The fuel spill prompted a hazardous-materials team to respond.
Carmageddon II isn't expected for another month, but after Thursday's traffic nightmare, some already feel like they have been through the worst.
"Luckily we had the GPS so it gave us a detour on the Sepulveda," said driver Patrick Johnson. "We tried to get around it because we heard about it on the radio. If we had heard about it sooner, we would have tried to dodge it."