Everybody knows what a cloverleaf looks like — but could you identify a volleyball, a double trumpet, or a “spooey” if you drove on one in the course of your highway travels? These are among the distinctive designs that transportation engineers have conjured up to keep traffic flowing and motorists headed in the right direction when major roads intersect.
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For your driverly edification, we’ve compiled photo examples of more than 2o different kinds of strange and delightful highway interchanges found both here in the US and abroad. In fact, right now stimulus dollars are being spent t0 build or upgrade many interchanges into one of these forms.
See Part 2 (with 11 more interchanges).
The Turbine – A “free-flow” style of exchange like the cloverleaf — that is, no traffic signals or intersections. This example is in Florida, at the junction of I-75 and I-4:
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The Cloverleaf – a classic, but it has fallen into some disfavor among traffic engineers because it causes weaving because cars are entering and exiting in the same lane. It also doesn’t handle large traffic volumes as well as some other configurations (for example, stacks).
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The Stack - A vertically layered arrangement of highways and connecting elevated ramps. The number of levels varies and go as high as six (though three and four are more common). Stacks are expensive to build but very efficient for high traffic volumes. This example is in Shanghai, but there are many stacked interchanges in the US:
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The Lofthouse: A roundabout over two grade-separated highways. Less expensive than than a stacked interchange, but also has much lower capacity.
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The ParClo – Or Partial Cloverleaf, a very popular design for places where interstates meet larger state and local roads. Depending how the loops and ramps are configured, a parclo is classified as either an A or a B and a number 1 through 4. This is an A-4:
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The Butt – A highly gluteal variety of the parclo. This example is in Germany:
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The Clovermill – A partial cloverleaf with turbine-style flyover (or, elevated) ramps:
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The Cloverstack – Combines elements of cloverleaf and stack designs. This rather feminine example is in Eastern Europe:
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The Spaghetti Bowl – When we get into the realm of shapes and patterns that seem to be describable only by chaos theory or string theory. Spaghetti is a global phenomenon these days.
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Classic Diamond – A simple and venerable design. It doesn’t eat up much land, but it can easily get backed up. This one is in Kentucky, near Louisville. (There is also a “Diverging Diamond” variant that involves driving on the “wrong” side of the road — for an example see this video showing one that’s being built in Utah.)
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The Spooey – The Single Point Urban Interchange (or, SPUI) is very compact and one of the best choices for tight spaces in cities. Unlike the diamond, it sends all traffic through one signal. The disadvantages of this arrangement are that it can be confusing to some drivers though, and it tends to be inhospitable to bikes and pedestrians. (See a visualization of a SPUI here.)
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The Braid – This Maryland interchange is a stack design, but what’s unique about it is that the north and southbound segments of I-95 and east- and westbound segments of I-695 are actually braided over each other briefly in the middle of the interchange. (See a diagram here.)
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SEE Part 2 of Crazy Highway Exchanges
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ALSO CHECK OUT ON INFRASTRUCTURIST:
HA! AMUSINGLY DEFACED STREET SIGNS
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CELL PHONE TOWERS PRETENDING TO BE TREES
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We’ve credited photos when the information has been available. Many are in the public domain. Satellite images from Google maps, Terraserver and Microsoft. If we missed any credits, please let us know.
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Top photo: GSGeorge
Tags: SHOW AND TELL
[...] Some great aerial photos of freeway interchanges. Some great planning and design going on here, making for some spectacular photos. Tags: exchange, freeway, photo aerial, road [...]
[...] – La Beauté des autoroutes Sauriez-vous identifier un “spooey” sur votre trajet autoroutier ? C’est la dernière trouvaille des spécialistes des transports pour fluidifier le trafic et permettre de garder la bonne direction dans les grands échangeurs. Problème : le dispositif peut perturber certains conducteurs et s’avère très contraignant pour les cyclistes et les piétons. Admirez ces “merveilles” ici: http://www.infrastructurist.com/2009/05/18/dont-pluck-the-cloverleaf-a-field-guide-to-highway-interc... [...]
[...] A Field Guide To Freeway Interchanges – Fascinating description of motorway/freeway interchanges. I didn’t know they all had names. The Maryland Braid is my favourite. [...]
[...] Us On Twitter Talking Trains With Michael Dukakis, Part 1 What’s A ‘Spooey’? A Field Guide To Freeway Interchanges, Part 1 Chart: America’s Streetcar Renaissance Ha! Amusingly Defaced Street Signs [...]
Mrsizer: “Beige, how amazingly convenient, then, that they are used by cars! It would be tragic to try to get cars onto something that was impenetrable except to rickshaws.
Form follows function, IIRC.”
I think you missed his point entirely, Mrsizer. What he was saying is not that they aren’t apt for their function, but rather they don’t play well with others. Not everyone trying to get around a city is in a car but some of these interchanges effectively crowd out all other transportation routes and modes. He’s remarking on the balance, or lack thereof, of some transportation infrastructure. If you need to go to a place a half a mile down the street (to a place you can see from where you are) but to do so you effectively need to either buy a car or walk 10 miles around, then that might be an indication of a problem of balance.
[...] Field Guide to Freeway Interchanges Part 1, Part 2 Posted by mariaoran Filed in Highway Bits ·Tags: I-10/610, infrastructurist, [...]
[...] [...]
Springfield, MO is getting a Diverging Diamond Interchange at Kansas Expressway (MO Route-13) and I-44. A big mess, but a fascinating mess. This youtube video seems to be the best demonstration I’ve found. http://www.youtube.com/watch?v=kQsM7lzhx1s (The one you linked to was awesome but they played with the camera motion too much, imho… )
Really awesome set of posts, and site. Thumbs up.
Here is a 5 way interchange that will be constructed in Fort Worth, TX.
http://www.youtube.com/watch?v=IxjVFhEm7iM
http://xkcd.com/253/
this is the best comment I could make, but done visually. I love good and well thought infrastructure that builds a strong foundation for the future. Modern Highways and especially interchanges are very rarely in this category.
[...] guide to highway interchanges: Parts 1 and [...]
[...] I love the scale of Interstates, the signs that direct you not from town to town, but from great city to great city: SOUTH—MIAMI; WEST—LOS ANGELES. These signs give me the same thrill as an international airport. They speak to the adventurer in me. I love the sight of a major interchange, with underpasses and overpasses cutting through the sky, shuttling us around in our little pods. This is industrial art on a most massive scale. (And I swear, I wrote this post hours before someone turned me on to this fabulous Field Guide to Freeway Interchanges.) [...]
please send me some useful information on interchange of highway with advantages and disadvantages
It’s interesting that you use the name “Lofthouse” in the US. The name comes from the UK junction between the M1 and M62 motorways near the village of Lofthouse (south of Leeds), which was one of the first of its type built in this country. But “Lofthouse” isn’t used as a generic term for that type of junction here.
The original Lofthouse interchange, like many others of the same design (M25/A2, M25/A20, M62/M57) has more recently had by-pass lanes added allowing some turning traffic to by-pass the roundabout altogether.
There’s a good reference site for UK road interchanges at: http://www.cbrd.co.uk/reference/interchanges/
If you want to see some whimsical looking interchanges, check some of the Gulf News archives to see some of the ones they built in Dubai. Here is several links:
http://www.parsons.com/Media%20Library/1208_Dubai.pdf
http://en.wikipedia.org/wiki/File:Dubai_Roads_on_1_May_2007.jpg
http://archive.gulfnews.com/articles/07/05/10/10124218.html (scroll thru the photos)
…or just zoom in on Google Earth……
[...] Highway interchanges from infrastructurist [...]
This is beautiful! I have dreams involving strange, convoluted freeway designs, so I find this beautiful.
Also, now I know what a spooey is! There are two in Bloomington, MN (well, between Bloomington and Richfield, spanning Interstate 494) and a third under construction. The first was 24th Street, redone to carry the anticipated new traffic loads when the nearby Mall of America opened. (It’s performed beautifully, BTW.) Several years later, the Penn Avenue bridge was demolished and replaced with a SPUI as part of the lead-in to Best Buy moving its headquarters to that location. (Basically, they were closing the roads *anyway*, so it was a good opportunity.) Now they’re working on doing the same on Lyndale Avenue, which probably needed it the most.
I used to call these “asterisk bridges” because they kind of resemble one from overhead. At first, I found them strange, but they really weren’t confusing. They’re actually pretty slick.
[...] What’s A ‘Spooey’? A Field Guide To Freeway Interchanges: Freeway Interchange Typology 101. [...]
Social comments and analytics for this post…
This post was mentioned on Reddit by mooseclamps: I live near where it’s going to be built, knowing how bad the drivers are here… I do not look forward to it….
My cruiser’s heart thanks you. These images are quite beautiful…
Spooey y otras soluciones usadas en autopistas para realizar cambios de dirección [EN]…
Lo de construir grandes carreteras es todo un arte. En este artículo recopilan varios de los diseños usados por los ingenieros para que los conductores puedan realizar cambios de dirección. Con alguno de ellos seguro que te topaste en alguna ocasió…
[...] Infrastructurist compiled photo examples of more than 20 different kinds of strange and delightful highway interchanges found both in the US and abroad. The Presurfer Comments [...]
[...] field guide to freeway [...]
i heart interchanges…
[...] I love the scale of Interstates, the signs that direct you not from town to town, but from great city to great city: SOUTH—MIAMI; WEST—LOS ANGELES. These signs give me the same thrill as an international airport. They speak to the adventurer in me. I love the sight of a major interchange, with underpasses and overpasses cutting through the sky, shuttling us around in our little pods. This is industrial art on a most massive scale. (And I swear, I wrote this post hours before someone turned me on to this fabulous Field Guide to Freeway Interchanges.) [...]
Is there some proper name for the land (often treed) that sits around the junctions. For example in a classic cloverleaf, there is land inside the ‘leaves’ of the clover and there is land bounded by the diamond of the ramps. Do these have a special name or any name for that matter?
What city is the picture of the loft in? I’m guessing that’s in china or somewhere in Asia.
These are beautiful when viewed from the air but they’re barriers when plopped down in the middle of a city. One of my favorites is the interchange for I-490, I-590 and NY590 in Rochester, NY – its known as the “Can of Worms” or the “Can” for short.
[...] I don’t know how serious these guys are about the naming conventions but the aerial photographs of highways interchanges are great dizzy-making fun. http://www.infrastructurist.com/2009/05/18/dont-pluck-the-cloverleaf-a-field-guide-to-highway-interc... [...]
strike out pitiable
erase miserable 45
They’re talking about a specific step by step method you’re doing everyday.
Great article. Waiting for more.
I’m trying to link back but do you have a permanent link format?
“The Cloverleaf – a classic, but it has fallen into some disfavor among traffic engineers because it causes weaving because cars are entering and exiting in the same lane.”
IMHO the root reason (entering and exiting in the same lane) is incorrect, as it appears in many others, like whorlpool.
The MD/I-95/I-695 interchange you call ‘braided’ I think is better known as the ‘Brit-flip’ since its main characteristic is that the major straight-through directions of traffic are ‘flipped’ to leftside or Brit driving through the interchange area.
The Brit-flip interchange is a neat design and simplifies the four lefthand turning movements. It is mostly at two levels, reduces the length and height of ramps required, avoids weaving movements, and provides rather direct routing for all movements. It’s one defect is that it breaks the traffic engineers’ rule that entries and exits on expressways must be on the rightside. I think this rule needs to be relaxed sometimes and that the Brit-flip IC should be on the menu of alternatives, especially where space and funding is limited.
You did not mention that with the widening of MD/I-95 north of the Baltimore tunnels to accommodate toll lanes the whole 95/695 interchange has been rebuilt to a more conventional expressway-expressway design with long director connector ramps. If you look now as opposed to when the picture was taken it is gone.
Very good resource. Add to bookmarks
It’s amazing how different the freeway systems can be depending on the need and the location. Most of the freeway interchanges in the here in the west United States are the diamond interchange. Some are a mixture of a diamond and a clover.
WoW! they’re beautiful….
[...] http://www.infrastructurist.com/2009/05/18/dont-pluck-the-clover…; [...]
Hi; I’m a civil engineer that is working on design of a circle that will work as a interchange. That’s a great and complicated design that we have ever did job.