It was usually parked in the Field Robotics garage, but if you went out early on a weekend morning, you might catch it driving itself slowly around Schenley Park (which is right next to CMU campus) – without anyone at the wheel, which was really unreal and sci-fi-ish at the time.
I remember one story of a jogger who was surprised to suddenly run across it. The story goes that the he or she screamed and actually fainted. The truck was programmed to stop if it found itself in front of any obstacle, so when the jogger came to, there was the truck looming above.
I have no idea if the story is actually true, but I like it anyway.