FlyerTalk Forums - View Single Post - Explain the "Diverging Diamond Interchange" to me...
Old Oct 6, 2015 | 10:21 am
  #31  
ajGoes
 
Join Date: Jul 2013
Location: DAY/CMH
Programs: UA MileagePlus
Posts: 2,474
Originally Posted by Cloudship
Never seen one of these. On first observation, I don't get what it is improving. You still have two lighted intersections, only now they are crossing each other and involve corners. You also have a bad crossing traffic - traffic exiting the highway not only has to merge with traffic, but the traffic entering the highway has to cross that merging traffic. And pedestrians have 4 major intersection crosses now.
In locations where heavy traffic from the highway would often interfere with traffic entering the intersection, a light can be added for the highway traffic.

Originally Posted by Cloudship
I guess I am still not getting what it supposedly improves.
It reduces the number of phases in the signaling system from six to two, thereby reducing the average wait time. Long waits to cross a freeway during rush hour should be significantly reduced.

It greatly reduces the risk of a serious accident caused by a left turn against traffic (in drive-on-the-right countries).
ajGoes is offline