Abstract: An underpass under an intersection has a first underground level for pedestrians, accessible by one or more pedestrian accesses from the street level, a second underground level for vehicles, accessible by one or more vehicle accesses from the street level, wherein the first underground level enables pedestrians to safely cross a street underneath the intersection, and contains establishments for the pedestrians, and the second underground level provides vehicle parking. In an embodiment, tunnels connect the levels under adjacent intersections. An improved method has the steps of installing one or more pedestrian levels below ground having pedestrian accesses at selected street corners on the street above, installing establishments in the one or more pedestrian levels, and installing one or more vehicle levels below the pedestrian levels having one or more vehicle accesses at the side of streets above, wherein vehicle levels provide vehicle parking.