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SFspiderman · 05-08-2018, 07:53 PM

Yes, that’s exactly what a DDI is. Looks weird on paper, but very efficient and not confusing when you actually drive it.

https://en.m.wikipedia.org/wiki/Dive...nd_interchange

pierretong1991 · 05-08-2018, 08:12 PM

Quote:

Originally Posted by zitsky

It almost looks like there are lanes crossing over from one side to the other, but that doesn't make sense to me.

Pretty colors are good. I like pretty colors. LOL

That's exactly what the design is.

Here's a video that explains the interchange concept:

https://www.youtube.com/watch?v=HD-0QnUlLOQ

(I typed something up but this video does a much better job LOL)

zitsky · 05-08-2018, 08:18 PM

I'd still like to kick the engineer who thought of this. Seems like it will be a huge headache.

pierretong1991 · 05-08-2018, 08:21 PM

Quote:

Originally Posted by zitsky

I'd still like to kick the engineer who thought of this. Seems like it will be a huge headache.

This is by far the biggest DDI I've ever seen. 10 lanes??

DPK · 05-08-2018, 08:28 PM

Quote:

Originally Posted by zitsky

I'd still like to kick the engineer who thought of this. Seems like it will be a huge headache.

Before people freak about about DDIs, I recommend watching this video:

https://www.youtube.com/watch?v=A0sM6xVAY-A

SFspiderman · 05-08-2018, 09:03 PM

Quote:

Originally Posted by pierretong1991

This is by far the biggest DDI I've ever seen. 10 lanes??

There's a new 12-lane one in Sarasota at I-75 and University Parkway. Four thru lanes, one turn lane, and one combined thru/turn lane on each side.

i75_DDI project

pierretong1991 · 05-08-2018, 09:07 PM

Quote:

Originally Posted by SFspiderman

There's a new 12-lane one in Sarasota at I-75 and University Parkway. Four thru lanes, one turn lane, and one combined thru/turn lane on each side.

i75_DDI project

It certainly looks like there's a lot more space in that picture compared to this interchange. This one is going to be really tight.

TrafficSys · 05-08-2018, 09:14 PM

The Sarasota one is the largest one I’m aware of (you beat me to it.)

Here’s a map of known locations.

Diverging Diamond Interchanges - Worldwide
https://goo.gl/maps/crRQ1FK5v2J2

In North Carolina there are 11 open, 2 under construction and 7 in design. Missouri, where the first one opened in 2009, is the only state with more.

Bull_City_Mom · 06-07-2018, 01:09 PM

I don't even understand why you're commuting in 2018. Seriously. Get fiber and work from home. What are you, a farmer?

architect77 · 06-07-2018, 01:22 PM

Quote:

Originally Posted by zitsky

I'd still like to kick the engineer who thought of this. Seems like it will be a huge headache.

It is a French invention and incredibly efficient, increasing throughput about 30-40% with much less time sitting and waiting for other directions to have their green time.

Atlanta has about 10 and have greatly improved regularly snarled areas.

Just two traffic signals are required at the crossover points.

They are just 2 phases alternating stop and go for your side or the oncoming side.

_______________________

By briefly switching sides, consider all of the signals not needed and all of the waiting for left turners on both sides of the freeway now eliminated.

We all make rights turns without needing a signal to do it safely, and this allows lefts to be made safely without needing the left arrow or worrying about yielding to oncoming cars.