I WAS DRIVING EAST AT 50 MPH ON CALIFORNIA HWY 68 AT 0800. IT WAS RAINING BUT THERE WAS NO STANDING WATER. I WAS DRIVING A 2003 TOYOTA PRIUS. AS I CROSSED THE INTERSECTION WITH SAN BENANCIO ROAD THE CAR SLOWLY SWERVED TO THE LEFT ACROSS THE ROAD, ENTERING THE OPPOSITE SHOULDER SLIDING BROADSIDE. THE CAR CONTINUED THE ROTATION, COMING TO REST FACING EAST AGAIN. I DID NOTHING TO INITIATE THIS BIZARRE EVENT. *JB