I made a right turn onto a gravel driveway that has a slight incline. My speed was less than 10 mph. At the top of the incline I attempted to make a U turn so I could park the car. Midway through the U turn the car’s acceleration increased rapidly to high speed without my stepping on the accelerator. I pressed the brake 3 times. The brake pedal went to the floor without seemingly any effect. In seconds the car traveled across the front lawn, picked up concrete from and old cistern top and smashed into the front porch tearing it off it’s foundation. Portions of the porch and tree limb fell shortly after the impact. The front tire was spinning at a rapid rate when I exited the vehicle. Extraction of the vehicle was not accomplished for 2 weeks while experts determined how best to accomplish the extraction. The car insurance company and 2 towing businesses declared the vehicle a total loss. The vehicle is with the towing company per car insurance company request. I don’t know if it has been inspected. I did not see any warning lights. I was treated at the hospital for a slight concussion and significant head and facial bruising and lacerations as well as a wrist burn likely caused by air bag deployment.