The person jumped onto the highway from the overpass at Mowry Avenue shortly after 5 a.m., prompting all southbound lanes of Highway 880 to be shut down, CHP Officer Tracy Hoover said.
Police blocked all the southbound lanes of Highway 880 from about 5:30 a.m. to 6 a.m., according to Hoover.
Traffic is reportedly traveling about 40 mph in the area since the lanes reopened.
The condition of the person who jumped is unknown, Hoover said.
