Fascinating look at highway traffic, from a perspective of social psychology:
WHY must a bottleneck develop at a merge zone? Well, obviously because there’s too many cars on one road. And because everyone must take turns slowly merging together. WRONG! Wrong wrong wrong. Even during extremely low-traffic conditions, everyone still takes turns, yet everyone merges as a high speed flow,like a zipper. A bottleneck never appears.
Traffic jams develop at a merge zone whenever the cars get so close together that there are no gaps between them. Without gaps, nobody can merge, and so the traffic suddenly comes to a near halt. The “gear teeth” jam up, the “machine” halts, and a bottleneck is created. The pile of pebbles can no longer pour through the funnel. Traffic on the highway turns into a city street intersection, where people merge at a “four way stop sign.”