I TURNED MY 2014 JEEP GRAND CHEROKEE WITH 24,400 MILES INTO MY FAMILY DRIVEWAY AND STOPPED BEFORE THE DRIVEWAY GATE. I LEFT 24 BETWEEN THE JEEP AND THE GATE SO THAT PEDESTRIANS COULD PASS IN FRONT OF THE VEHICLE WHILE I WAS OPENING THE GATE. I PUT THE JEEP IN PARK AND WITH THE ENGINE RUNNING AND WHILE STILL SEATED BUT WITH MY FOOT OFF THE BRAKE, I REACHED OVER TO THE PASSENGERS SEAT TO GRAB MY BAG FOR THE KEY. AFTER FINDING THE KEY, I EXITED THE RUNNING VEHICLE KEEPING THE DRIVER'S DOOR OPEN. I WALKED AROUND THE OPEN DOOR, STOPPED IN FRONT OF THE CAR AND UNLOCKED THE GATE. I THEN OPENED THE LEFT HALF OF THE GATE PUSHING IT ENTIRELY BACK TO THE WALL. I THEN PROCEEDED TO WALK BACK TO THE CENTER OF THE GATE TO OPEN THE RIGHT HALF OF THE GATE. I PULLED THE GATE ROD FROM THE HOLE IN THE GROUND SO I CAN MOVE THIS SECTION OF THE GATE, AND JUST AS I DID, THE JEEP BEGAN TO MOVE TOWARD ME HITTING THE FAR RIGHT GATE POST WITH THE RIGHT FRONT CORNER OF THE VEHICLE. I WAS SHOCKED AND RAN BACK AROUND THE OPEN DRIVERS DOOR AND INTO THE CAR TO BACK IT AWAY FROM THE POST. WHEN I ENTERED THE VEHICLE, I FOUND IT IN PARK, AND I SELECTED REVERSE TO BACK IT OFF THE GATE POST. FROM THE TIME I EXITED THE VEHICLE, IT WAS ABOUT 45 SECONDS BEFORE IT MOVED. IF I MISTAKENLY LEFT IT IN DRIVE, IT SHOULD HAVE BEGUN MOVING AS SOON AS I REMOVED MY FOOT FROM THE BRAKE PEDAL AND REACHED ACROSS TO THE PASSENGERS SEAT FOR MY BAG. EVEN IF I MAINTAINED MY FOOT ON THE BRAKE AT THAT TIME, IT SHOULD HAVE MO