1,100 tiny cars roam endlessly over a cityscape in Metropolis II by artist Chris Burden.
"The exhibit, when running, requires two full-time attendants: one standing inside it monitoring flow like a panopticon, and another pacing around the 20-by-30-foot installation watching for traffic snarls. "I've seen spectacular pile-ups involving cars that spill off the road and derail trains," Burden says. "Every hour 100,000 cars circulate through the system, so you're going to get some glitches. It's not digitized."