Diverging Diamond Visualization

Simulation of a Diverging Diamond operation

Category:

Autos & Vehicles

Tags:

• visualization

[cscottblev]

Concerning if there is a POWER OUTAGE (top voted comment):

The DDI function without any confusion. The geometry will guide drivers to the correct location with the only difference being that there will be a full stop condition at the crossovers instead of a signal control. This is one of the advantages of the DDI over the single point urban interchange (SPUI) or a continuous flow interchange (CFI).

[csh000]

If one were to exit the green expressway to fill their gas tank at the corner store and want to continue on the expressway, how is that possible when the service road doesn't cross the intersection?

[Astat1Go]

Yes, I've seen this in crop circles.

[marigolds6]

@pdhpool "And what the heck happens when the stopped traffic backs up to the criss-cross section?" It can't. Traffic storage backs up into the through road and the arterial, not into the criss-cross. That is why the outside lights go red before the inside lights to red. The dorsett interchange does not even fill up half of the criss-cross storage area during rush hour.

[marigolds6]

This intersection also handles problems much more easily. e.g. power outages, stalled cars, speeders etc. Since there is no left turn lane, that gives an extra through lane to navigate around obstacles. The one time there was a power outage, each light becomes a 2-way stop sign. Extremely smooth to navigate compared to a 4-way stop.

[marigolds6]

I live right next to one of these on Dorsett Rd and I-270 in the St Louis region. Dorsett is a major high traffic arterial. The intersection is very easy to follow; while driving through it, driving on the left feels more correct. It is also much safer than the previous cloverleaf because there are no simultaneous merge on-merge off zones. Traffic can get up to speed right away without making room for exiting merges. The drawback? If you get off the wrong exit, there is no way to get back on.

[mylmyl100]

@stevecycle2 I'd imagine it'd actually be easier to navigate than your standard 4-way intersection. In both cases, with the lights out, you treat the intersection as a "stop sign." In your traditional 4-way intersection, you have to watch cars coming from 3 directions--left, right crosstraffic, and oncoming traffic turning left across your lane. In this intersection, you have two intersections, yes, but you only have to worry about traffic from one direction coming across your lane.

[fuzzypinkturtle]

We have two in Springfield, they are amazing.

[dplots]

@deepthreat cloverleafs take up a huge amount of space to build because of the wide turning radii required for allowing trucks to make the u-turns. In urban areas such land is often not available, so the SPUI has been used. Single-Point Urban Interchange. However the SPUI has considerable signal delay from all of the left-turns. This seeks to eliminate that.

[deepthreat]

How is this mess better than a cloverleaf ?

[JungleJil]

I'm also curious as to how this is superior to a clover leaf layout, with no stop lights and no left turns at all?

[NobodobodoN]

@jjamska: The Blue Lanes are a "limited-access highway", like a Freeway. There are entrance/exit ramps just outside the area shown which allow merging on and off those. The grey lanes to the side are the "feeder road" or the "access road".

Many places (eg Texas) have these access roads for nearly every interstate. Where I grew up, they were pretty rare (though maybe they have them now), so this would have confused me, too.