In downtown Chicago, near where the river meets the lake, the city gets a bad case of Escheritis. The streets double—sometimes triple!—into three dimensions, dropping below each other and folding around the basements and sub-basements of skyscrapers, cutting across the river on bridges hanging below other bridges, and eliding into drivable strata in ways that cities generally promise not to do. In Chicago, the multi-level streets of Wacker, Lake Shore Drive, Michigan Ave.