The diverging diamond interchange comes to St Louis.

[Jesda]

[youtube]http://www.youtube.com/watch?v=JIypFKBz4YI[/youtube]

Summary: When driving under the highway, motorists switch to the opposite side of traffic. In theory, this would effectively reduce congestion making it easier to merge on and off. The problem is that I don't trust my fellow motorists to figure it out.

The motorists here:
I grew up in Belleville IL with a large roundabout in the town square, and people understood how to use it because it was in the middle of downtown, but when I see them appear in the rest of the STL metro area, especially in the suburbs, I worry. Some drivers believe that traffic already in the circle doesn't have the right of way, or that they can enter the circle without checking for traffic.

I'm going to check out this new interchange tonight or tomorrow.

[nissangirl74]

Wear a helmet

[Razi]

Inb4 texting teen screws up.

[sx moneypit]

The idiots around here would never figure it out.

[Loki]

I drove a couple DDIs in Phoenix, AZ last year. It's a little funky at first, but it seemed like most people understood it.

[wingFeather]

What the???

[simmode1]

I must be stupid or something cause what I just saw in that video scared the hell out of me. Maybe it's just the Memphis in me, but if I had never been to that part of town and had to go through that thing, WTF would certainly be my reaction.

[ADDirishboy]

I drove a couple DDIs in Phoenix, AZ last year. It's a little funky at first, but it seemed like most people understood it.

Um, what? Where in the hell were you? I don't think I've ever seen one here...

[AZ89two4Tsx]

I drove a couple DDIs in Phoenix, AZ last year. It's a little funky at first, but it seemed like most people understood it.

Um, what? Where in the hell were you? I don't think I've ever seen one here...

I must always go the wrong way on them then.

[ADDirishboy]

I'm seriously confused now. I've driven damn near every inch of freeway in this state and have NEVER come across something like that.

[OriginalWheelman]

This is such a bad idea its not funny. Yeah, getting off the interstate is easier, and EVERYTHING ELSE is more complicated. There are just as many lights, and traffic on the cross-road can only go one way at a time. This will be great when the idiots pull into the intersection and block it on both sides. Gridlock.

[wingFeather]

There probably aren't any & Loki is just unknowingly causing great mayhem LOL

[PoorManQ45]

This is such a bad idea its not funny. Yeah, getting off the interstate is easier,

That's the thing I worry about.

From what I saw in that they expect the traffic on Dorsett road to stay in their own lane.

If the drivers are anything like they are here they'll go into whatever lane they want.

I still don't understand how this is better then a standard setup. You still have the same number of lights...

[Loki]

I drove a couple DDIs in Phoenix, AZ last year. It's a little funky at first, but it seemed like most people understood it.

Um, what? Where in the hell were you? I don't think I've ever seen one here...

I'm sure I drove through at least one somewhere in south Scottsdale....I didn't have anything to drink that week :eek

[themadscientist]

"traffic signals will welcome you" WTF? Do you have friendlier signals there? Mine seem to say "STOP MUTHA****ER!"

[Dattebayo]

"traffic signals will welcome you" WTF? Do you have friendlier signals there? Mine seem to say "STOP MUTHA****ER!"

You have black stoplights?

[AZ89two4Tsx]

I'm seriously confused now. I've driven damn near every inch of freeway in this state and have NEVER come across something like that.

Maybe he's thinking of the intersection between Grand Ave. and McDowell in ghetto Phoenix. Seeing as Grand runs diagonal compared to all the other streets, there's like a 6 way intersection. Can get pretty confusing.

The only other place I can think of is like Cave Creek and 7th street.

I've been ALL around the phx area multiple times too.

[themadscientist]

"traffic signals will welcome you" WTF? Do you have friendlier signals there? Mine seem to say "STOP MUTHA****ER!"

You have black stoplights?

Perhaps. When I find myself next to another fast car the green light directs me to "BREAK THAT MUTHA****ER OFF SUM!"

[Razi]

Jesda needs to do voice-over work.

[JimmyMethod]

Why can't we just get http://en.wikipedia.org/wiki/Roundabout

[themadscientist]

Because then we get this.

[youtube]http://www.youtube.com/watch?v=KMKTPZ6i ... re=related[/youtube]

[ADDirishboy]

Maybe he's thinking of the intersection between Grand Ave. and McDowell in ghetto Phoenix. Seeing as Grand runs diagonal compared to all the other streets, there's like a 6 way intersection. Can get pretty confusing.

The only other place I can think of is like Cave Creek and 7th street.

I've been ALL around the phx area multiple times too.

Not sure how that can be confused with a DDI though. No one is crossing over anywhere. It can be kind of a f*** if you're trying to turn and haven't been there before though.

Loki, you must be thinking of a different state. Cause I'm almost 100% sure that there isn't a DDI in AZ.

[RCA]

Tourists driving when the interchange isn't busy and drunks will kill this idea.

[Jesda]

Looks better in person. They used tall concrete curbs and walls to make it inconvenient to turn into oncoming traffic. When the directions switch, the turns are so sharp that it looks like a T intersection, encouraging the driver to go through the intersection to the other side rather than making a 90-degree right.

[Razi]

I'm glad they took some provisions to make sure nobody goes to the wrong side of the road.
Quite a cool idea, the diamond interchange.

[simmode1]

"traffic signals will welcome you" WTF? Do you have friendlier signals there? Mine seem to say "STOP MUTHA****ER!"

You have black stoplights?

Oh god... new sig! Thanks guys!

[fiznowler]

We have had these for a year or 2 now. They actually flow a ton better than the old system. You have to be pretty stupid to not be able to figure it out. It does feel pretty damn wierd to drive in the other lane of traffic before you get used to it though.

[wingFeather]

Roundabouts >

Less lights, more fun.

[MinisterofDOOM]

There are goofy wrong-side-of-the-road intersections in Salt Lake. To me, it seems less like "safer" and more like trading one downside for another. And the new one is one people aren't familiar with.

http://www.udot.utah.gov/i/udot/ucon/cfi_anim.swf
I fail to see how adding MORE stoplights equals "continuous flow" any more than the normal way of doing things. I also don't see how sticking two new lights a half-block down the road is any less of a delay for through-traffic than a protected turn arrow. The video makes it sound like you'll rarely get stuck at that light, but traffic on Bangerter is heavy and moms in minvans accelerate slowly. In reality, this just means one more light on the way to your destination.

If it ain't broke, fix it 'till it is, right?

[RCA]

Looks better in person. They used tall concrete curbs and walls to make it inconvenient to turn into oncoming traffic. When the directions switch, the turns are so sharp that it looks like a T intersection, encouraging the driver to go through the intersection to the other side rather than making a 90-degree right.

I hope people stay safe out there.