The collision happened shortly before 5 a.m. when a car slammed into the center divider near Burbank Boulevard, according to a CHP incident log. As many as four vehicles were blocking lanes after the incident.
Southbound lanes were backed up as far as the 118 Freeway, and motorists were urged to use Sepulveda Boulevard as an alternative route.
The SigAlert was canceled just before 9 a.m. and all lanes were reopened, the Highway Patrol said on Twitter.
The cause of the crash was unknown.