WHILE DRIVING ABOUT 65 MPH AND CRUISE CONTROL SET, CONSUMER TAPPED BRAKE TO SLOW DOWN. INSTEAD, VEHICLE MAINTAINED SPEED. CONSUMER THEN APPLIED BRAKE HARD, AND CRUISE CONTROL WOULD NOT CUT OFF. CONSUMER STEERED VEHICLE TOWARD MEDIAN, AND HIT A GUARDRAIL. VEHICLE WAS TOTALLED, CONSUMER NOT INJURED.*AK