A cement truck overturned along northbound State Route 125 just south of H Street in the Eastlake area of Chula Vista.
The incident occurred just after 7 a.m. and closed all lanes of the northbound South Bay Expressway for several hours.
Two people were transported to Scripps Mercy Hospital for what officials described as minor injuries.
California Highway Patrol officers said the accident happened as the driver of the cement truck attempted to change lanes and lost control of his vehicle.