The collision was called in at about 6:30 a.m. on Highway 238 just south of the flyover between Hayward and San Leandro, CHP Officer Peter Van Eckhardt said.
A white pickup truck reportedly overturned after colliding with a big rig and a van, Van Eckhardt said.
Van Eckhardt did not know whether anyone was injured.
A Sig-alert issued at 6:45 a.m. was lifted at 7:40 a.m.
