I misspoke. Ever since I lived close enough to Morgantown to visit there a few times a year, I always called the PRT there a "monorail". That's what other people I knew called it, and that's what it looks like when you're not in one of the cars. Turns out, it operates on a heated paved surface and the cars run on rubber tires. But it is powered by electricity. So I guess it's technically not a light rail system, but it is a Personal Rapid Transit system (the only operating one in the world, according to what I've read).