As you may have heard, MODOT opened up the first Diverging Diamond Interchange (DDI) (http://en.wikipedia.org/wiki/Diverging_diamond_interchange) at I-44 and the Kansas Expressway (MO-13) in Springfield, MO.
It's a rather curious design that I have mixed feelings on. MODOT has plans to build several more, and here in Oregon, ODOT wants to build one at the I-5/Fern Valley Rd interchange in Phoenix, OR.
As such, I'm kind of interested as to what my fellow roadgeeks think about DDIs.
-Alex (Tarkus)
Have to drive one to find out...
I think DDIs have been unfairly denigrated, especially on MTR. There is a lot of fear that the crossovers will lead to wrong-way travel, but I think this is misplaced and FHWA's Turner-Fairbanks Highway Research Center seems to agree with me (http://www.tfhrc.gov/safety/pubs/07048/index.htm). DDIs allow designers to get some of the queue management benefits of a SPUI without having to replace an existing bridge crossing, with all the traffic management impacts that implies.
It remains to be seen how critical provision of positive guidance is to the proper operation of DDIs. I-44/SR 13 will provide early experience, but MoDOT is confident enough in the basic design that it already has at least two other DDIs in the works (I-435/Front Street and one of the three jobs involved in the Page Avenue contract in this month's letting).
if people can manage to not drive the wrong way down an off-ramp, they can handle the DDI. Lots of big red DO NOT ENTER signs, and execution of drunk drivers, should solve the problem.
Quote from: J N Winkler on June 22, 2009, 07:52:42 PM
It remains to be seen how critical provision of positive guidance is to the proper operation of DDIs. I-44/SR 13 will provide early experience, but MoDOT is confident enough in the basic design that it already has at least two other DDIs in the works (I-435/Front Street and one of the three jobs involved in the Page Avenue contract in this month's letting).
The DDI bundled with the Page Avenue interchange with I-270 is actually on I-270 at the Dorsett Road interchange.
There is a third DDI planned for the US 65/Chestnut interchange in Springfield, MO:
http://www.modot.org/springfield/major_projects/Greene/ChestnutExp65.html (http://www.modot.org/springfield/major_projects/Greene/ChestnutExp65.html)
And I still say the name should be changed to "Crossover Diamond Interchange" since it's more descriptive.
Another advantage over a conventional diamond which hasn't yet been mentioned is the ability to do a U turn from the freeway without passing any traffic lights. This could be useful in the event of ramp closures at nearby interchanges.
Really, the greatest flaw with it is that it's strange and new, so drivers aren't used to it and may not handle it properly.
You build enough of them and people get used to it, that won't be a problem anymore.
Quote from: Revive 755 on June 22, 2009, 09:28:08 PMThere is a third DDI planned for the US 65/Chestnut interchange in Springfield, MO:
http://www.modot.org/springfield/major_projects/Greene/ChestnutExp65.html (http://www.modot.org/springfield/major_projects/Greene/ChestnutExp65.html)
If that is MoDOT's third, then I have found a fourth. Call number 801 in the July 24 letting is for another DDI in Springfield, at the US 60/National Avenue interchange. This job provides guide signing on a more generous scale than the I-44/SR 13 DDI, with overhead lane assignment signs guiding traffic straight ahead (to stay on National Avenue) or down ramps to US 60.
A diverging diamond is one of the alternatives for the I-590/Winton Road interchange (https://www.nysdot.gov/portal/page/portal/regional-offices/region4/projects/590winton).
I believe this is the interchange in question...
http://www.youtube.com/watch?v=c4p-d-6EnOQ
Quote from: Hellfighter on June 24, 2009, 04:36:58 PM
I believe this is the interchange in question...
http://www.youtube.com/watch?v=c4p-d-6EnOQ
That's freaking awesome :wow:
There are more Diverging Diamonds planned in other areas in the U.S.
http://en.wikipedia.org/wiki/Diverging_diamond_interchange (http://en.wikipedia.org/wiki/Diverging_diamond_interchange)
I drove it and wasn't sure what to think. Maybe I'll go back after all the construction work is completed in 2-3 weeks.
As far as going the wrong way, the local NBC station reported it took less than an hour for someone to go the wrong way after the DDI opened. :pan:
It's not really too, too confusing. Everything is just reversed from regular, everyday U.S. driving.
Be well,
Bryant
What a pain in the ass!
That is an interesting design.
Quote from: US71 on July 01, 2009, 12:49:09 AM
As far as going the wrong way, the local NBC station reported it took less than an hour for someone to go the wrong way after the DDI opened. :pan:
The signage looks quite clear, though it would help if they could have finished the barriers before opening it up to traffic (the way they have it in the video, it looks like a temporary situation due to construction). If that person can't follow signs they shouldn't be allowed to drive in the first place.
Hellfighter, thanks for sharing that video--it's cool to see it in its actual operating conditions. I'm finding myself increasingly warming to the DDI. I'd definitely be more comfortable with one of those than a dumbbell or raindrop interchange.
-Alex (Tarkus)
I'm surprised NJDOT hasn't graced us with one of these to confuse drivers even more.... heck we don't even have a real SPUI in this state yet.
Quote from: NJRoadfan on July 01, 2009, 05:30:43 PM
I'm surprised NJDOT hasn't graced us with one of these to confuse drivers even more.... heck we don't even have a real SPUI in this state yet.
Hehe and I know just where to put one too :)
Quote from: NJRoadfan on July 01, 2009, 05:30:43 PM
I'm surprised NJDOT hasn't graced us with one of these to confuse drivers even more.... heck we don't even have a real SPUI in this state yet.
Drive up to CT Exit 48 off the Merritt Parkway with CT Route 111.
Quote from: NJRoadfan on July 01, 2009, 05:30:43 PM
I'm surprised NJDOT hasn't graced us with one of these to confuse drivers even more.... heck we don't even have a real SPUI in this state yet.
NJ 133 at NJ 33, coming soon.
The Penn's Neck US-1 bypass is supposed to have 2 as shown in the preferred alternative, who knows when thats getting built.
A diverging diamond has been floated recently as a way to remodel the US 190/LA 22 interchange in Mandeville.
This looks cool, i want to go on this
BigMatt
That interchange just made diamond interchanges awesome. I usually like more complex interchanges (which this is), and this is one nice interchange. I am sick of normal diamonds (just about). But this just put some fresh thoughts about diamonds into my mind. This is one great interchange!
http://www.youtube.com/watch?v=t0YUd3KD0AE
My real-time trip through the diverging diamond a couple of days after it opened.
so how many drivers know this is permanent, and not just some wacky construction zone?
Interesting stuff.
I so wanna drive that now!
Diverging Diamonds are coming to SimCity soon! See this topic in Fictional Highways (https://www.aaroads.com/forum/index.php?topic=2110.0) for the discussion. Please keep this thread on topic!
This just in, Indiana is planning on building this type of interchange in conjection with the East End Bridge Project between Utica and Louisville in Southern Indiana.
http://www.courier-journal.com/article/20100119/NEWS01/1190302 (http://www.courier-journal.com/article/20100119/NEWS01/1190302)
Looks interesting. I doubt I'll be seeing any in Newfoundland any time soon. :D
Quote from: tdindy88 on January 19, 2010, 05:26:59 PM
This just in, Indiana is planning on building this type of interchange in conjection with the East End Bridge Project between Utica and Louisville in Southern Indiana.
http://www.courier-journal.com/article/20100119/NEWS01/1190302 (http://www.courier-journal.com/article/20100119/NEWS01/1190302)
I'm not sure a DDI would be better than just removing the loop in the SE quadrant and leaving the interchange as a six ramp partial cloverleaf; I'd like a few more details than the article provides regarding traffic operations and the cost of widening the EB IN 265 overpass.
Quote from: Revive 755 on January 19, 2010, 09:54:38 PM
Quote from: tdindy88 on January 19, 2010, 05:26:59 PM
This just in, Indiana is planning on building this type of interchange in conjection with the East End Bridge Project between Utica and Louisville in Southern Indiana.
http://www.courier-journal.com/article/20100119/NEWS01/1190302 (http://www.courier-journal.com/article/20100119/NEWS01/1190302)
I'm not sure a DDI would be better than just removing the loop in the SE quadrant and leaving the interchange as a six ramp partial cloverleaf; I'd like a few more details than the article provides regarding traffic operations and the cost of widening the EB IN 265 overpass.
I looked into it a bit more and saw that the website for the project had an illustration of how the interchange would look and included a video of how the intersection would work with traffic.
http://www.kyinbridges.com/project-newsroom/2009-12-diverging-diamond.aspx (http://www.kyinbridges.com/project-newsroom/2009-12-diverging-diamond.aspx)
The simulated vehicles at 2:44 in the first video are worrisome.
Good thing the train had already just gone through...
^^ Yeah, I agree. That railroad crossing would work better being grade-separated than at-grade.
Be well,
Bryant
To me the length of the left side driving part of the interchange looks too long.
I'd also like to see how the northern half of the interchange is performing while a train is blocking the south side.
Quote from: Revive 755 on January 20, 2010, 12:35:56 PM
I'd also like to see how the northern half of the interchange is performing while a train is blocking the south side.
I would too. And, yes, I agree with Bryant that grade separating the RR crossing would be a good thing assuming that the level of rail traffic is sufficient enough to warrant it. If the track only sees one train a day, the grade crossing is probably fine.
MoDOT is now planning another DDI for the US 65 interchange with MO 248 in Branson:
http://www.news-leader.com/article/20100128/BREAKING01/100128008/1007/NEWS01/Branson+aldermen+approve+diverging+diamond (http://www.news-leader.com/article/20100128/BREAKING01/100128008/1007/NEWS01/Branson+aldermen+approve+diverging+diamond)
Bumping this thread up a little. It seems Google's updated the StreetView in Springfield, MO, and you can now take a virtual drive (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Springfield,+MO&sll=37.249598,-93.310833&sspn=0.031018,0.077162&ie=UTF8&hq=&hnear=Springfield,+Greene,+Missouri&ll=37.250964,-93.310661&spn=0.064904,0.154324&t=h&z=13&layer=c&cbll=37.251082,-93.310665&panoid=LkRtu_ymycwqkID29MeJqA&cbp=12,161.18,,0,1.5) through the I-44/MO-13 Diverging Diamond.
Enjoy!
-Alex (Tarkus)
I have a video of me driving through it just a couple of days after it opened.
http://www.millenniumhwy.net/videos/Diverging_Diamond.mp4
The second one is now open, also in Springfield MO. And they just started a third.
The one in American Fork UT will be open in a month.
MO now has a total of 7 planned, under construction, or open.
Quote from: Troubleshooter on July 29, 2010, 10:42:23 AM
The second one is now open, also in Springfield MO. And they just started a third.
The one in American Fork UT will be open in a month.
MO now has a total of 7 planned, under construction, or open.
Where are the other ones in Springfield? I have family there, so I visit there a lot and I'd like to know where to look for them. I really like the one at I-44 and MO 13.
Quote from: Revive 755 on June 22, 2009, 09:28:08 PM
And I still say the name should be changed to "Crossover Diamond Interchange" since it's more descriptive.
I prefer the term "Death Diamond".
Quote from: huskeroadgeek on July 29, 2010, 02:59:30 PM
Where are the other ones in Springfield? I have family there, so I visit there a lot and I'd like to know where to look for them. I really like the one at I-44 and MO 13.
James River Freeway (US 60) at National. There is also a tunnel under National to access Cox Hospital
Quote from: huskeroadgeek on July 29, 2010, 02:59:30 PM
Quote from: Troubleshooter on July 29, 2010, 10:42:23 AM
The second one is now open, also in Springfield MO. And they just started a third.
The one in American Fork UT will be open in a month.
MO now has a total of 7 planned, under construction, or open.
Where are the other ones in Springfield? I have family there, so I visit there a lot and I'd like to know where to look for them. I really like the one at I-44 and MO 13.
The third just started is at Chestnut Expressway and U.S. 65.
Quote from: Revive 755 on June 22, 2009, 09:28:08 PM
And I still say the name should be changed to "Crossover Diamond Interchange" since it's more descriptive.
The US DOT prefers "double crossover diamond."
Merged posts -Connor
Quote from: deanej on June 24, 2009, 03:27:29 PM
A diverging diamond is one of the alternatives for the I-590/Winton Road interchange (https://www.nysdot.gov/portal/page/portal/regional-offices/region4/projects/590winton).
And that's what it will be reconstructed into.
Quote from: doofy103 on July 01, 2009, 08:56:46 PM
Quote from: NJRoadfan on July 01, 2009, 05:30:43 PM
I'm surprised NJDOT hasn't graced us with one of these to confuse drivers even more.... heck we don't even have a real SPUI in this state yet.
Drive up to CT Exit 48 off the Merritt Parkway with CT Route 111.
For SPUIs, there's also NY 25/Suffolk CR 97 on Long Island.
Quote from: mightyace on January 20, 2010, 05:07:01 PM
Quote from: Revive 755 on January 20, 2010, 12:35:56 PM
I'd also like to see how the northern half of the interchange is performing while a train is blocking the south side.
I would too. And, yes, I agree with Bryant that grade separating the RR crossing would be a good thing assuming that the level of rail traffic is sufficient enough to warrant it. If the track only sees one train a day, the grade crossing is probably fine.
I live about 3 miles from that RR crossing, and I have NEVER had to stop for a train.
It looks fine to me. Maybe what they need to do is build a barrier on the cross-over so you can't see the traffic on the "wrong" side of the road....at least as a short term measure.
TDOT is about to open up TN's 1st and the nation's 5th diverging diamond interchange, this one with the highway going over the intersecting street, making it the 1st in the country of this type:
http://news.tennesseeanytime.org/node/6468