ANTIOCH (CBS SF) -- An overturned big-rig blocked a portion of state Highway 4 in Antioch for about four hours Saturday morning, according to the California Highway Patrol.
Officers responded to a report of a motorcycle crash on westbound Highway 4 near Contra Loma Boulevard around 7:10 a.m., CHP officials said.
While officers were en route to the scene, the CHP received a report of a second crash minutes later involving a loaded cement truck that had overturned at the same location.
The unrelated collisions happened along a stretch of westbound Highway 4 under construction where only two lanes were open, according to the CHP.
An investigation showed that the big-rig driver for an unknown reason drifted his vehicle to the left and lost control after he sideswiped a concrete rail along the center median, CHP officials said.
Both lanes were blocked after the truck overturned and came to rest on its side, according to the CHP.
Crews were able to contain diesel on the road from the fuel tank and wet concrete from a bin on the truck, CHP officials said.
The big-rig driver was able to remove himself from the vehicle and did not suffer any injuries, according to the CHP.
Two tow trucks were needed to position the big-rig on its wheels, CHP officials said.
A Sig-alert was issued around 7:40 a.m. and the lanes reopened shortly after 11 a.m.
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