RED BLUFF, Calif. -

Traffic was slowed on southbound Interstate 5 through Red Bluff Monday morning.  A big rig carrying a load of PVC pipe overturned at the Antelope Boulevard on-ramp.

The accident happened at 6:40 a.m. Monday. 

The freeway was reduced to one lane for most of the morning.

As of 10:15 a.m., both lanes were back open, but the southbound Interstate 5 on-ramp from westbound Antelope Boulevard remained closed.