Car Accelerates On Its Own problems of the 2001 Jeep Grand Cherokee

I washed my 2001 Jeep Grand Cherokee at a coin operated car wash. I climbed into the car, started it up and shifted from park to drive. The car went to full throttle instantly on it's own. I applied brakes but that had little affect and the car rapidly accelerated out of the car wash stall toward a brick wall approx. 20 feet away. I steered the car into a tree as I felt it would be a softer crash as opposed to a wall. The car bounced off of the tree and continued at full throttle into the driveway of the car wash as I continued to push on the brake pedal as hard as I could. I finally turned the key off and stopped. This happened very quickly and I wish I would have reacted sooner. The left front fender and grill were damaged and I had the car towed to a repair shop. I feel fortunate that nobody was hurt and I am very interested in finding the cause of this .

Brakes vibrate and do not slow vehicle adequately. When slowing transmission downshifts into low gear and vehicle accelerates and lurches forward. To compensate for this sudden acceleration additional pressure on the brake pedal is required to avoid loosing control. This is unsafe and will cause an accident if not addressed properly.