There are few things that demonstrate the excesses of the Automobile Age better than amusement parks, with their promise of adrenaline-fueled escapism spread over vast suburban tracts that always seem to be a two-hour car ride from wherever you are. Not that anyone would suggest ridding the masses of their right to whiplash and vomit. One architect’s proposal: Relocate theme parks to the city. Then build ‘em up. Waaaaay up.