All lanes of state Highway 238 at Interstate 680 in Fremont were blocked Thursday afternoon after a tractor-trailer overturned and spilled a load of sand onto the roadway, according to the California Highway Patrol.
The crash is under the jurisdiction of Fremont police, who said it was reported at 2:47 p.m. after the big-rig overturned while exiting 680 onto northbound Highway 238, also known as Mission Boulevard.
The big-rig driver was alert and conscious, and an ambulance responded to the scene, police said.
The road is expected to remain closed for several hours, and motorists are advised to avoid the area, police said shortly after 4 p.m.
No further information was available.