A Sig Alert was issued Wednesday night around 8:15 p.m. for the closure of all I-80 westbound lanes near Ashby.
As of 9:25 p.m., the right and center westbound lanes have reopened, while the two left lanes remained blocked.
The left lanes on I-80 were also blocked but have since reopened.
CHP said closures occurred after a vehicle hit a pedestrian on I-80 at around 7:50 p.m.
The incident started with a chase involving the Contra Costa County Sheriff’s Office. A red SUV and a gray SUV were involved in the crash.
CHP said a person stepped out of the red car and was struck by the gray car. That person was hospitalized with major injuries.