I TURNS MY TOYOTA SIENNA INTO A DRIVEWAY OF A STORAGE FACILITY AND PLACED THE VEHICLE INTO PARK WHILE TRAFFICPASSED BY AS THIS ROAD WAS ALSO THE EXIT ROAD FROM COSTCO. WHEN IT WAS SAFE FROM OTHER VEHICLES AND IS WAS SAFE TO BACK OUT OF THE DRIVEWAY I TOOK THE VEHICLE OUT OF PARK AND SUDDENLY THE VEHICLE LURCHED FORWARD RAMMING INTO AN IRON GATE BENDING IT WIDE OPEN. THE VEHICLE CONTINUED THROUGH THE GATE EVEN THOUGH I TURNED OFF THE IGNITION , JAMMED MY BRAKES AN TRIED TO PLACE IT INTO PARK ALL TO NO AVAIL. CONTINUING THROUGH THE GATE I WAS ABLE TO REACH A LARGE OPEN AREA WHEREUPON I TURNED THE STEERING WHEEL AS HARD AS I COULD TO MAKE SURE THE VEHICLE WOULD ONLY CIRCLE. AFTER A BIT OF TIME THE ENGINE ROARED PICKUP SPEED THEN STOPPED. THIS SAME SURGE OCCURRED ON SEVERAL OCCASIONS BUT I THOUGHT I DID SOMETHING TO CAUSE THIS PROBLEM. *TR