The University of Michigan, together with the Michigan Department of Transportation, developed a test environment that would enable car manufacturers and technology suppliers to test driverless cars in a controlled environment. Called Mcity, the 32-acre site simulates both urban and suburban environments through a network of roads with intersections, traffic signs and signals, streetlights, fake building facades, sidewalks, and obstacles such as construction barriers. Unlike public streets, most of Mcity’s elements are movable so engineers can rearrange the city’s layout to create complex intersections, blind corners, and a variety of other conditions. Mcity also contains robotic pedestrians that pop out in front of traffic unexpectedly to see how well autonomous vehicles react. The market for driverless technology is expected to grow to $42 billion by 2025, and self-driving cars may account for a quarter of global auto sales by 2035.