Fischel’s explanation begins with trucks and buses, which forever changed the spatial geometry of the city. Before big, gas-powered vehicles took over the streets, it was easy to keep the different functions of the city separate. If you didn’t want to live near a manufacturing plant or the masses of workers who worked in it, you could always live (or build) somewhere else. Trucks and buses changed that. “The truck liberated heavy industry from close proximity to downtown railroad stations and docks,” Fischel writes.33 Factories could now be located anywhere. Buses liberated urban workers, too.
