THE FIRST INCIDENT OCCURRED WHEN MY WIFE AND I WERE PICKING UP MY GRANDDAUGHTER AT HER HOME LOCATED ON A STEEP HILLSIDE WITH A STEEP DRIVE PROBABLY 8 PLUS DEGREES. I PUT THE CAR IN REVERSE AND STARTED TO BACK DOWN THE DRIVE. I HAD TO BACK OVER THE CONCRETE DRIVE EDGE AS I HAD PULLED OFF INTO THE YARD TO MAKE ROOM FOR HER PARENTS VEHICLE. TO GET OVER THE EDGE I HAD TO PRESS LIGHTLY ON THE ACCELERATOR. I HAVE FREQUENTLY BACKED DOWN THE DRIVE USUALLY IN IDLE. THE MOMENT I PRESSED THE ACCELERATOR THE CAR IMMEDIATELY WENT INTO FULL THROTTLE. I JAMMED THE GEAR SHIFT INTO PARK , PULLED THE EMERGENCY AND PRESSED AS HARD AS POSSIBLE ON THE BRAKE. NOTHING SLOWED OR EVEN SEEM TO EFFECT THE BACKWARD ACCELERATION. I HIT A RAILROAD TIE THAT WAS ONE OF MANY THAT DEFINED THE DRIVE. THE FRONT TIRE LITERALLY EXPLODED. I WAS ABLE TO STEER DOWN THE DRIVE ONTO THE ROAD AROUND A GREATER THAN 90 DEGREE TURN BACKWARDS AND UP HILL. THE RIM DUG INTO THE ASPHALT , THE CAR STOPPED AND ENGINE SHUT OFF. WE PUT ON THE SPARE AND DROVE HOME. TWO DAYS LATER, IN THE SAME PLACE, I STARTED TO BACK ONTO THE DRIVE AS BEFORE. I WAS VERY MUCH AWARE OF THE SITUATION AND THEREFORE WAS VERY CAREFUL TO SEE THAT THERE WAS NO OVERLAP OF FOOT ON BRAKE AND ACCELERATOR. I ALSO THOUGHT THAT IF THAT TERRIBLE INCIDENT WERE TO REPEAT ITSELF I WOULD TURN OFF THE KEY. WHEN THE BACK TIRE CAME IN CONTACT WITH THE DRIVEWAY LIP I ONCE AGAIN I HAD TO PRESS THE ACCELERATOR TO GET ON THE DRIVEWAY. SAME TERRIBLE RES