Is there a city that has successfully done this?

I have seen this interchange design pop up before, but now they are proposing it up at I-88 and Rt 59 in Naperville.

http://youtu.be/kF-IU-1lDzU

Has somebody done this and has it worked for traffic congestion and prevented accidents like this supposedly supposed to do?

We have a few of them newly built in this area. I was tempted to get a lawn chair and watch the carnage on opening day, but no real problems

Apparently a lot of cities have them; http://www.divergingdiamond.com/

I ran one of them going from Rt 9 onto I 87 north of Albany.

No big deal.

There are several of them in the Minneapolis-St. Paul area, one is about a mile from where I sit right now. They work fine.

My big concern is, how busy is 59? I haven't been on it in about 5 years, but from what I remember it was pretty busy. This will guarantee that both directions will have to stop at least once at a stop light. Not ideal.

On the other hand, it effectively makes a really long exit which would help with the back up into 88. So maybe it is the only thing that would work.

From their FAQ:

http://www.divergingdiamond.com said: Q) Are you serious? A) Heck no! This is an awful idea and we just sort of drew it up as a joke. You're not really putting one of these things in, are you? You're going to kill everyone!

Popping up all over St Louis and I'm pretty impressed by them. They work very well.

Optimizing getting on and off the freeway. Seems like a pretty good idea to me.

There are a number of them just north of Atlanta. They're less confusing in practice than they look - at least once most drivers who pass through them figure out what they are.

It looks better than those "traffic-circles".

Saw this a while back...hope to see it more in the future.

Try putting one of these in:

I could see some having some "issues", especially in the middle there.

Or you could always:

Oh my!

Took me a while to see how it was more than a marginal improvement, but it does make sense.

In reply to aircooled:

sales of RWD cars would skyrocket.

Making the merging traffic and exiting traffic take place on different sides on the road makes a lot of sense as it streamlines the flow to pass through traffic in the middle lanes and everyone in the left and right lanes should be going the same place.

In reply to aircooled:

Look kids, Big Bed, Parliment:

There's one in Lexington, KY at Beaumont Circle.... So far nobody has really killed themselves, yet.

also, I feel this design is 2 small underpasses away from perfection.

In reply to aircooled:

My hometown has a double mini roundabout. It's on a semi-major road, and my hometown is full of retirees. Imagine how that goes.

In reply to G_Body_Man:

I would imagine it doesn't...

In reply to Lancer007:

You'd be right about that. It's also just before the Senior's Centre. Whoever thought that up was related to Lucas, Prince of Darkness.

YES! Define 'successfully'.

they just put one here in Columbia and it seems to work okay. The radius on the turns merging for the Interstate suck but that's not an inherent design flaw.

Huh. There's one in my state, and I've driven on it without even noticing it. Must work pretty well.

In reply to foxtrapper:

You don't really notice the good roads, just the bad ones.