When I left the house, I didn't turn on the cruise control. I don't use cruise control unless I am driving long distances. When the car began to accelerate by itself, after I had finished passing another vehicle, and I looked at the gauges on the dashboard, I was surprised to see the cruise control was on. I immediately cancelled the cruise control, and shut it off, but was annoyed that, when I looked again, it was still on! I shut if off a 2nd time, and pulled off to stop the acceleration problem I was having, which was potentially very serious. Since this is the first time I have had this problem, it will be watched very closely from now on.