Mass-transit cranes

Mount a large horizontal beam, with a motorized pivot, atop every large building in a city centre. The radius of each beam will obviously be limited by the distance to the nearest taller building (if not by gravity).

A system of pulleys allows a large elevator-style passenger car to be lowered to ground level from either end of the beam (and, obviously, to be lifted again). With a bit of clever design, the cars at opposite ends of the beam will largely counterbalance one another - as one car goes up, the one at the other end of the beam goes down.

Passengers can be picked up at a number of stations spaced around the perimeter traced out by the beam on the ground and, after a short but exciting ride (up; round; down) deposited safely and swiftly at any other point on the same perimeter. If all large buildings are suitably equipped, passengers can swap cars at points where the tangents of two cranulators almost touch.

Note that there is nothing to stop a small-radius cranulator operating entirely inside a larger-radius cranulator, provided obviously the inner cranulator is mounted on the shorter building. Wheels within wheels.

With a little bit of integrated control and good insurance, it might even be possible for the cranulators of adjacent buildings to "mesh" with one another, and to actually pass cars from one system to the next, allowing passengers to move across town without even needing to descend in order to change cars.