Two vehicles were involved in the crash on northbound Highway 280 just south of Black Mountain Drive at about 5:40 a.m., CHP Officer Kevin Bartlett said.
Minor injuries were reported and three right lanes were blocked for nearly an hour, he said.
Black ice has been reported on Highway 280 on the Doran Bridge, which spans Crystal Springs Road near the Crystal Springs Reservoir, Bartlett said.
It had not been determined if ice was a factor in the crash, he said, and Caltrans was responding to abate the problem.
A National Weather Service freeze warning remains in effect for much of the Bay Area outside of San Francisco, which includes a warning to motorists that patchy ice could be encountered on regional roadways.
The warning remains in effect until 9 a.m.