I guess having it zoned would allow for alternate uses like putting up isolation walls and using it as additional storage; or just parking a movable storage container in the spot.

The loading dock is a very useful part of the concept, as is the necessity of a /community/ garage encouraging all moving vehicles to operate on a distinct layer from pedestrian areas.

It would not be uncommon to have lawns, pathways, even a park or garden above such a garage.

In a denser area the streets could actually be moved entirely underground, aside from some access roads that /normally/ wouldn't be used as such. (Special permits to bring in LARGE cranes/etc.)

Also, it would be required of the area /building/; if you don't need that particular piece of property then I can easily imagine it being leased to nearby businesses as part of their parking allocation.