EXITING DRIVEWAY TO 4 LANE DIVIDED HIGHWAY FROM COMPLETE STOP. CAR STATIONARY.RELEASED BRAKE PEDAL TO MAKE LEFT TURN.BEFORE TURNING WHEEL, CAR ACCELERATED BY ITSELF, WHEN I LIGHTLY APPLIED GAS,AT GREAT RATE OF SPEED AND COULD NOT BE STOPPED OR SLOWED BY APPLYING BRAKES.HAD TO STEER CAR INTO CONCRETE POLE ON WHICH THE TRAFFIC LIGHT RESTED IN DIVIDED AREA TO STOP VEHICLE.