This is an elaborate solution for highway congestion with more than 4 converging highways that somewhat resembles how air traffic is managed in ascent and descent corridors. Really, converging more than 4 highways should be avoided, but IF traffic planning demands it: Imagine 2 elevations of street. The lower level is dedicated to a spiraling set of entrance ramps that converge at an expanded radius roundabout. Traffic enters the roundabout from the outside lane. Traffic leaves the roundabout from the inside lane. Exit ramps spiral upward at a steep grade from the inside lane to the second level and bank outward. The steep grade on exit slows traffic, allowing for tighter turns in shorter distances.