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In part one of this series, we saw examples of highway interchanges known as The Cloverstack, The Lofthouse, and The Butt (see above). In this installment, we’ll examine three way interchanges (think trumpets and T-bones) and see a strange and unique case of “braided” freeways.
The Trumpet – A classic design for an interchange where one highway is ending into another:
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The Double Trumpet – Tends to occur where toll highways are linked by a short segment of roadway. This one is in Belgium:
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T-Bone: Also known as a “semi-directional T,” this is an option where one highway ends into another.
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Directional T - Much like the T-bone, but minus the flyover ramps.
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The Full Y: At a merging point of two highways. There is also a “Partial Y” version, which has a less complete ramp structure than the example below.
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The Whirlpool – Quite similar to the turbine pictured in part 1. This example is in the UK:
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The Braided Cloverleaf - An unusual configuration:
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The Circle – While not an ideal design, sometimes the best option for tight urban spaces. This one is in Chicago:
(Photo)
“The Pure Triangle” – the intersection of highways A5 and A7 in Germany:
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The Volleyball – So named because it looks like the stitching pattern on a volleyball. It is very space efficient but not designed to handle large volumes of traffic. Similar to the lofthouse, but with more of a square shape at the center.
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“The Single Leaf”: A bizarre junction in the Netherlands — serves only one of eight possibilities:
SEE: A FIELD GUIDE TO HIGHWAY INTERCHANGES, PART 1
SEE ALSO: AMERICA’S STREETCAR RENAISSANCE (MAP)
and COMPARISON SHOPPING FOR TRANSIT SYSTEMS (CHART)
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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, let us know.
Tags: SHOW AND TELL
I can’t take no more!
[...] The Daily Dig What’s A ‘Double Trumpet’? A Field Guide To Freeway Interchanges, Part 2 [...]
[...] + Part 1 + Part 2 [...]
Hey,
are you sure that the Double Trumpet is in Belgium?
AFAIK Belgium doesn’t have toll stations except one at the Liefkenshoektunnel near Antwerp. May that Interchange possibly be in France or Spain?
Other than that, great collection of pictures!
Kind regards from Germany,
-dp
I’m with Anonymous!
Single Leaf … is not.
That particular example seems to serve *two* possibilities. Isn’t that a plain exit serving the “opposite flow” of the cloverleaf? It’s the “opposite corner” from the leaf. It appears to have’s own mini-collector lane (although I’m not clear on why a single exit only would need a collector).
Any chance of a Google Maps link so we can see the context?
Thanks for both part 1 and part 2
In starkville, MS, we used to have a single leaf junction EXActly like that one pictured.
They’ve updated it a smidge, but see for yourself:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=starkville,+mS&sll=35.976805,-78.906843&sspn=0.821272,1.41037&ie=UTF8&ll=33.472815,-88.761442&spn=0.006614,0.011019&t=k&z=17
There is only one thing that matters, to a driver, about an interchange: can I turn around?
If you’re a driver, you’ve been there: you missed your turn because you couldn’t get in the right lane, the signage was crappy, or you were distracted at just the wrong moment.
So, you are now driving along a strange section of highway, as yet uncharted by you. You drive to the next junction, and go off there, hoping that it’s not one of the total bastard ones that don’t let you turn back on yourself. By the time the junction itself is in sight, you’re already committed to the turn.
And if you’re unlucky, you find yourself forced onto a completely unknown road, driving to the next junction on THAT one, in the hope that you can turn around there.
And if you’re unlucky, you end up on a third road, by now hopelessly lost…
So, fair warning: any highway planner I meet, if I find they have ever in their life planned such a junction, I will punch them in the face.
“Dumbbell” Interchange–like a diamond, but with one roundabout at each intersection instead of stop signs or traffic signals. There is one in Vail, Colorado (Google Maps takes you straight to it by typing in “Vail, CO”)
the circle in chicago is so painful to drive. always, ALWAYS backed up.
don’t forget to dig up a diverging diamond. I believe there is one somewhere in France.
This doesn’t seem to fit any of your categories. Might I suggest – chaos.
@Dewi Morgan
I’d like to punch the person who put road signage so low that it can be blocked by trucks. I ended up on a strange road on the way from Lyon to Clermont-Ferrand in France because all of the signs for the road I should have taken were hidden by a long line of trucks in the right lane.
*goes to install Transport Tycoon Deluxe
I’ve always wondered about this sort of thing and envied the US and the clean and logical designs they go for, usually because they have the luxury of space and most things are new so they don’t have to consider many existing roads. Here in the UK, our interchanges can be crazy. I never got this one whenever I drove on it, it made no logical sense and the traffic backing up was a nightmare!
http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&q=Donnington+Park+Circuit,+Castle+Donington,+Isley+cum+Langley,+Leicestershire+DE74+2,+United+Kingdom&sll=52.713835,-2.426605&sspn=0.300329,0.889893&ie=UTF8&cd=2&geocode=FbQVJgMd8_7q_w&split=0&ll=52.855048,-1.297417&spn=0.009666,0.027809&t=k&z=16
This interchange in Toronto is known as The Basketweave.
@Dewi Morgan
I totally agree! And from that perspective, turbine and whirlpool look horrible (although they are said to be efficient).
[...] The beautiful and terrifying geography we have wrought in the highway [...]
Of course the British “cloverleafs” are more complicated. They drive on the wrong side of the road.
Try the High 5 Interchange in Dallas, Tx. For the driver it is easy to navigate. At the time it was the largest single highway construction project in the history of the state.
http://maps.google.ca/?ie=UTF8&ll=43.718761,-79.499903&spn=0.013709,0.022552&t=k&z=16
[...] the beginning of last week, A Field Guide to Interchanges (part one // part two) on [...]
[...] here recently, becoming immersed in identifying satellite photos of double trumpets and whirlpool exchanges and so on. After seeing our features on the subject, tipster sent sent us these more whimsical [...]
what kind of interchange would this be?
http://maps.google.com/maps?f=q&source=s_q&hl=en&q=Springfield,+Massachusetts&sll=36.456636,-95.712891&sspn=47.698782,66.796875&ie=UTF8&cd=1&geocode=FVFvggIdUHCs-w&split=0&t=k&ll=42.136152,-72.626088&spn=0.00545,0.012231&z=17&iwloc=A
[...] Field Guide to Freeway Interchanges Part 1, Part 2 Posted by mariaoran Filed in Highway Bits ·Tags: I-10/610, infrastructurist, interchange [...]
A good example of a Volleyball is visible at Lee Highway and Fairfax County Parkway in Fairfax, VA.
enf_kh1: There is a similar example in Poughkeepsie, where US 44 crosses US 9. When I worked in the Poughkeepsie NYSDOT office, we called it the “bowtie” or “bugseye.”
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=poughkeepsie&sll=42.638159,-73.961164&sspn=0.011144,0.018625&ie=UTF8&ll=41.702316,-73.937119&spn=0.005655,0.013379&t=k&z=17&iwloc=A
Here’s another odd one: left-hand entrance and exit ramps converge to a single intersection, rather than a conventional diamond:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=sprain+brook+pkwy&sll=42.708678,-73.783493&sspn=0.089054,0.149002&ie=UTF8&ll=41.123178,-73.81032&spn=0.002853,0.006689&t=k&z=18
My favorite whirlpool is in Albany, NY, down the hill from the state capital:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=12201&sll=42.638159,-73.961164&sspn=0.009771,0.011845&ie=UTF8&ll=42.644195,-73.750373&spn=0.004885,0.009989&t=k&z=17&iwloc=A
Highway Engineer Pranks:
http://xkcd.com/253/
looks like that single leaf serves 2 of 8–there’s a ramp at the top of the pic.
There’s always my favorite, the Mixmaster in Waterbury, CT:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=waterbury+ct&sll=41.55076,-73.050842&sspn=0.011931,0.019248&g=plainville+ct&ie=UTF8&ll=41.552815,-73.049898&spn=0.011931,0.02738&t=k&z=16
They’re building a diverging diamond in American Fork, UT: http://www.udot.utah.gov/pioneer/gallery2/main.php?g2_view=core%3ADownloadItem&g2_itemId=240
A circle within a circle, near Asbury Park, NJ:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=asbury+park+NJ&sll=41.123784,-73.810176&sspn=0.005973,0.013937&ie=UTF8&hq=&hnear=Asbury+Park,+Monmouth,+New+Jersey&ll=40.225786,-74.036999&spn=0.003027,0.006968&t=h&z=18
Volleyballs aren’t named because of the stitching pattern. This explains it more:
http://www.kurumi.com/roads/interchanges/volleyball.html
Besides, it doesn’t even look like the stitching pattern.