Chris Brown, © Museum Associates/LACMA

In a sign that building enthusiasts are moving on from Legos to other building toys, the Los Angeles County Museum of Art is displaying Metropolis II, an almost-10-foot-high and 28-foot-wide kinetic sculpture, made with steel-beam armatures and plastic roadways, that depicts a city in motion. Three electrically powered, magnet-studded conveyor belts move toy cars to the top, then release them to race past buildings down 18 roads, including a six-lane freeway, at 240 scale miles per hour—simulating L.A.’s notorious traffic and congestion. Four years in the making by local artist Chris Burden, the sculpture is now on long-term loan to the museum, running on weekends during scheduled times. Each hour it operates, 1,100 mini autos vroom through the arteries and main drags 91 times each. •