At approximately 13:12 CST on [XXX], I exited the car wash at a gas station in Rochester, MN. I drove around to the front of the gas station to park so I could go inside to replenish the car wash card. At approximately 13:13 CST, as I was turning right, pulling into the parking space near the entrance, the truck accelerated unexpectedly and collided with a cement parking pilon (sp?). I am unsure how this occurred. I believe the vehicle may have accelerated on its own. Holding my foot hard on the brake, I shifted into reverse, then backed the truck up about 2 feet from the pilon, turned off the vehicle and went outside to assess the damage. There was front end passenger side damage to the vehicle and the pilon casing was ripped and the top was pushed halfway off. Thank God that pilon was there to stop the vehicle and avoid hitting the building or pedestrians. At the time I was parking I am sure I was driving less than 5 mph, but I am unsure how fast the vehicle got to in that 15-20 foot acceleration. When the vehicle hit the pilon it was very jarring. The impact threw my glasses off my face, flung my backpack from the passenger seat to the front passenger floor, and caused my cases of soda pop and bags of groceries in the trunk area to shift forward and to rip the paper grocery bags. My right thumb and the right side of my neck were sore that evening and I had a minor headache as well. This Ford Expedition Max has approximately 35K miles on it. It is a well maintained compa