A busy crossroads where north-south traffic crosses without stopping. East-west traffic is accelerated via conveyor belts to fly above the north-south traffic like the General Lee. turning left or right is a problem,so detours are required. A sort of power-assisted flyover-- giligamesh, Jan 13 2009 The General Lee http://www.generalleeone.com/. [Sir_Misspeller, Jan 13 2009] [+] on general principles but how is this superior to a bridge ?-- FlyingToaster, Jan 13 2009 //how is this superior to a bridge ?//A bridge could collapse, and that would be dangerous.-- coprocephalous, Jan 13 2009 One could adapt this same principle to address problem potholes by simply erecting ramps in front of them.-- bungston, Jan 14 2009 random, halfbakery