A Sig-alert was issued at 5:33 a.m. after a series of collisions reported at about 5:20 a.m. blocked at least two lanes of westbound I-80 at San Pablo Dam Road, CHP Officer Jonathan Short said.
The two rightmost lanes remained blocked while fire crews worked to clear the vehicles involved in the crashes.
The CHP cancelled the Sig-alert at 6:12 a.m. once those lanes reopened.
Although at least three vehicles were involved in the collisions, Short said it was unclear whether the vehicles were involved in separate crashes or if one crash led to the other.
At least one person was transported to Kaiser Permanente Medical Center in Richmond with minimal injuries, Short said.