Eternity RPC Board
04-11-2018, 08:27 PM
(This post was last modified: 04-11-2018, 08:28 PM by Seperallis.)
On the topic of traffic engineering and interchanges, I came across another one today that I'm really excited about because I'm a boring old adult: the "diverging diamond." This dude has a great video on it (and I think I might subscribe to him for other things too), but the concept is, once again, to keep traffic moving and reduce wait times. It's most common use is to alleviate problems at popular intersections between a highway/interstate and an over/under-crossing arterial street.
The biggest problems at these popular interchanges is 1) the increased danger of mishaps as you try to make turns across traffic lanes, and 2) the huge delays to traffic flow by having to accommodate turns across traffic lanes. The conventional method of designing an interchange is to have two four-way traffic lights, one on either side of the bridge that spans the larger interstate/highway; as we already know from the Michigan Left solution, reducing the number of cycles for the light reduces wait times. But what if you can not only keep highway traffic flowing without a stop, but also eliminate all but two lights and make it so two directions ever stop?
![[Image: DDI_rendering.jpg]](http://www.gwinnettcounty.com/static/departments/transportation/images/DDI_rendering.jpg)
Only the people going straight through on one of the roads ever have to stop, meaning the cycle only has two lights. In the meantime, all turning traffic has unobstructed lines of sight to make their turns, and are never attempting to make a turn across oncoming lanes of traffic. I think this has a huge advantage of traffic flow over a Michigan left for many situations. Hell, depending upon your needs and traffic flows you could even implement roundabouts into the pattern and eliminate all traffic lights.
This shit's fascinating, yo. This is what gets me excited in my old age. Talk civil engineering with me:
http://imgur.com/gallery/VPHBI
http://www.youtube.com/watch?v=HD-0QnUlLOQ
http://i.imgur.com/XOWrJlf.jpg
The biggest problems at these popular interchanges is 1) the increased danger of mishaps as you try to make turns across traffic lanes, and 2) the huge delays to traffic flow by having to accommodate turns across traffic lanes. The conventional method of designing an interchange is to have two four-way traffic lights, one on either side of the bridge that spans the larger interstate/highway; as we already know from the Michigan Left solution, reducing the number of cycles for the light reduces wait times. But what if you can not only keep highway traffic flowing without a stop, but also eliminate all but two lights and make it so two directions ever stop?
Only the people going straight through on one of the roads ever have to stop, meaning the cycle only has two lights. In the meantime, all turning traffic has unobstructed lines of sight to make their turns, and are never attempting to make a turn across oncoming lanes of traffic. I think this has a huge advantage of traffic flow over a Michigan left for many situations. Hell, depending upon your needs and traffic flows you could even implement roundabouts into the pattern and eliminate all traffic lights.
This shit's fascinating, yo. This is what gets me excited in my old age. Talk civil engineering with me:
http://imgur.com/gallery/VPHBI
http://www.youtube.com/watch?v=HD-0QnUlLOQ
http://i.imgur.com/XOWrJlf.jpg