When I lived in the San Francisco Bay Area I used to go to indoor short-track races at the Cow Palace. The track, which the rest of the time was the floor of a hall where they held car shows and livestock auctions and crafts exhibitions, was cement or concrete, and looked as slippery as ice, but the traction was astounding, and the racing was cut-throat. I have some photos from one of these events where Kenny Roberts and Steve Eklund duked it out like the two masters of the craft they were; I'll get around to posting them soon.
Meanwhile, here's a video of an indoor supermoto race, shot from a helmet camera. It combines short track and road racing in a space that looks about the size of a 7-Eleven parking lot. I'd love for this to catch on here. I'd pay to see it. (Right now I'd pay to have the music track scorched from my memory.)