Innovative new interchange by MODOT

[Lzen]

Missouri Department of Transportation photo shows the diverging diamond interchange, the first in the U.S., at I-44 and MO 13 in Springfield, Mo.

A new type of interchange could have drivers thinking they’re in the UK if it ever spreads across the States. It has the potential to keep traffic moving more quickly in and out of freeways while reducing left-turn conflicts.
It’s called the diverging diamond.
The principle behind it is to flip the direction of traffic on the surface street before it passes over or under the freeway. Using only two standard signalized intersections, the two travel directions on the surface street cross each other before and after passing through the interchange. It looks like left-hand drive.
While flipped, they allow for unimpeded left turns – there is no longer any oncoming traffic – both onto the freeway entrance and off of the freeway. Once traffic returns to right-hand drive, the other ramps allow unopposed right turns on and off the freeway.

[Lzen]

[Marco Polo]

Makes sense.

[philfree]

It's kind of wierd driving on the left side of HWY.


PhilFree

[Frazod]

Originally Posted by Marco Polo

Makes sense.

It does, but having driven in Southern Missouri, I can tell you, this is a recipe for disaster.

[talastan]

Actually I live about 2 miles from this interchange and the traffic has improved 10 fold IMO. I love it...No more getting stuck behind people trying to make a left onto I-44.

[Lzen]

Originally Posted by philfree

It's kind of wierd driving on the left side of HWY.


PhilFree

Yes, that would feel really strange. But I gotta say that it is very intelligently designed.

According to Don Saiko with MoDOT...“Left-turning cars in traditional interchange designs have intermittent access to the freeway and are more likely to collide with oncoming vehicles, especially when yielding to through traffic,” Saiko said. “The diamond interchange allows left-turning traffic to go through the interchange faster and more safely,” he said.

The design is also financially appealing because it uses existing lane space without requiring new land for additional bridge structure, he said. It cost $3 million to install the design compared with the $10 million for a bridge, which prompted MoDOT officials to try it.

“The interchange has delivered. The number of crashes within the interchange plunged by 60 percent from June to October of 2009 from the same months of 2008,” Saiko said. “And, he said, it has solved the clogging problem in commutes.”

[DMAC]

Yep...works good. They are putting another one at James River Freeway and National, I believe.

[Pants]

That's a beauty. Great job by MODOT.

[Demonpenz]

I have driven it several times it seems ok you just have to watch what you are doing. I remember getting in town and waiting there for 15 minutes. 15 minutes on an already long ass drive is a pain in the ass

[Marco Polo]

Originally Posted by frazod

It does, but having driven in Southern Missouri, I can tell you, this is a recipe for disaster.

I remember when the first double turn lanes were put in at the small town where I grew up in Iowa. Several accidents the first few days; people get used to it after a few times though.

[Ralphy Boy]

It works perfectly. They are putting another one on the south side of town near Cox Hospital at National & James River Freeway.

[Ebolapox]

it works like a charm, or has the few times I've been on it.

[Bugeater]

That's pretty ingenious. When they built the West Dodge Expressway here in Omaha they put in a couple of interchanges like this:



It still requires the two left turn lanes but at least it only uses one set of lights for the entire interchange instead of a separate set on each side of the freeway.

[chefsos]

I like that. Simple and clever.