Black ice was reported on a portion of Interstate 280 near the scene of a crash in Hillsborough Tuesday morning, a California Highway Patrol officer said.
Two vehicles were involved in the crash on northbound Interstate 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 Interstate 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 roads.