The accident that involved as many as four vehicles was reported at 8:45 a.m. near the Geneva Avenue off-ramp. A Sig-alert was issued at 9:06 a.m., CHP Officer James Evans said.
The alert was canceled and the three lanes reopened at 9:47 a.m., according to the CHP.
At least one person suffered major injuries in the multi-vehicle collision, Evans said.
Traffic had been backed up into Daly City after the crash closed the lanes, according to Evans.
In a separate incident in the same area on the highway, debris was reported in the roadway at 8:35 a.m. Apparently a lawn mower was blocking two lanes, but has since been cleared off the road, the CHP said.