On [XXX] at [XXX] I dropped my wife and 2 children off at the Funland Arcade in Deep Creek, Maryland. The parking lot was full from the holiday weekend and I was planning on taking the Lightning to a nearby charger while the family gamed so I double parked perpendicular to the arcade entrance, put the hazards on, and let them out. After the 3 of them got out, I placed the Lightning in reverse to back up 5-10 feet so that I could exit the parking lot through the same way I came in. Once I had enough space from reversing so I could make the turn to exit I placed the Lighting in drive. The moment the Lightning switched to drive it accelerated at a very high speed as if I was flooring the gas pedal, which I was not. The lightning was in one-petal mode which I always use unless Iâm on a highway. I immediately began pumping the brakes but the truck would not stop, I probably slammed on the brake petal 4-5 times to no avail. I even tried shifting the truck back into park but it would not shift out of drive. I was able to luckily steer the truck into a hillside approximately 150 feet away. The truck ran over numerous small trees and shrubs before crashing to a stop approximately 16 feet up the hill. Shortly after the shock wore off, I slowly reversed the truck down the hill, exited the truck, and informed dozens of onlookers who came out of the arcade to see what the noise in the parking lot was from, that the truck just took off on its own but that I was fine. I called 911 a