84 replies to this topic

[Rardy]

Let's compare freeway exit designs we're familiar with - the functional, the obsolete, the bizarre, and the extreme.

This is an odd one from Charleston, WV, the I-64 exit at Maccorkle:


My personal favorite, the SPUI (single point urban interchange), requires only one red light for left-turning traffic exiting the freeway.  Here's Nonconnah at Winchester Road in Memphis:


And of course, the 4-level stack.  This is I-49 at the Inner Loop Expwy in Shreveport, LA:

[dtown]

They just completed a sweet new interchange here in Michigan, about an hour from my house. Its 2  round-abouts. Its located at M-81 at I-75 near Saginaw. This interchange can get really bad back ups, so hopefully this speeds up traffic flow.

I dont have a real pic, but heres an artists rendering.
http://www.michigan...._1_155180_7.pdf

[richyb83]

Great topic ; Thanks Rardy for those interesting interchange pics.

thanks for posting that too dtown.

[SBCmetroguy]

Rardy, on Dec 12 2006, 04:25 PM, said:

And of course, the 4-level stack.  This is I-49 at the Inner Loop Expwy in Shreveport, LA:

Those are all interesting, especially the design of that first one!

But I have to say I love the one I included with this reply. I drive on that thing every single day. It's about 25 miles from my house, but it's real close to my office and is my quickest route to work. The ramp that comes in at the top-middle of this photo, and then swoops down and off to the right, is the one I take every morning; and of course the farthest one to the right is the one I take every evening.

That long one I take every morning is FUN. It starts out as 2 lanes wide, so it gives me an opportunity to get up to 70-80 to pass other cars, and see how fast I can go around it before I go up on 2 wheels. I've still yet to actually achieve that goal.

[tracer1138]

If you look closely, that first one is really just a double trumpet. They're more common than you may think.
You often find them at interchanges between tollways and other highways/high capacity roads because the tollboths can be easily arranged in a signel plaza on the connector.

[TBurban]

The infamous Springfield, Virginia Mixing Bowl!  Traffic can be backed up for miles and hours during DC/Baltimore/Northern Virginia rush hour.

[Dozer]

Ironically - I have a strong distaste for highways, but love studying the different types of interchanges. Here are a couple from Massachusetts, since I am most familiar with this area:


This one is from Auburn, MA, at the junction of I-90, I-290, U.S. 20, and MA-12. Though not unique by design, the size is what makes this stand out. I've always been fascinated by the fact that, despite this complex interchange, one must still get off on to MA-12 coming from I-290 N in order to get on to I-90. There is no direct connection between the two highways coming from northbound I-290! Anyhow, moving on...


This one is from my home town of West Springfield. I always loved the quadruple-trumpet feature of this elongated interchange connecting I-91, I-90, and U.S. 5.


Another from West Springfield, featuring I-91 and U.S. 5 again (about a mile south of the previous interchange). The design of this interchange, though not particularly unique, I think is a more efficient use of space, requiring less than a typical cloverleaf, but is more costly, requiring two under/over passes, and having limited merge space coming on and off of the Intersate.


From Weston.. this interchange is actually a large rotary. I-95 (128) & U.S. 20.


Lastly, I thought I would post the Fort Point Channel I-93/I-90 Interchange and crossing in Boston.  Just one-tenth of a mile long, the Fort Point Channel crossing cost $1.5 billion, the most expensive highway per mile in the world.

That's all from me today.  

Edited by Dozer, 13 December 2006 - 08:08 AM.

[dgreco]

a providence interchange.

[Dozer]

dgreco, on Dec 12 2006, 11:08 PM, said:

a providence interchange.

I spin my wheels on that thing every day! Always a good time.. LOL  

[b3nr]

Oh wow. These are absolutely amazing! Many are completely unique too. The land take of some of these is astonishing. My favourite would have to be the quadruple trumpet junction!

The UK has nothing on these. This is debatably our most complicated interchange, known as as spaghetti junction: http://maps.google.c...&...mp;t=k&om=1

[dgreco]

b3nr, on Dec 13 2006, 06:30 AM, said:

Oh wow. These are absolutely amazing! Many are completely unique too. The land take of some of these is astonishing. My favourite would have to be the quadruple trumpet junction!

The UK has nothing on these. This is debatably our most complicated interchange, known as as spaghetti junction: http://maps.google.c...&...mp;t=k&om=1

That is still a big jumble of roads, I think theese are even nicer in person, I love to see highways overlapping each other

[Recchia]

I love SPUI's!  

That mixing bowl in DC looks quite scary. Anybody have some of the 401 interchanges in Toronto? Those must be nuts with all those lanes.

Here's the I-95/US 1/US 9 interchange in New Jersey approaching the George Washington Bridge into New York:

[Rardy]

b3nr, on Dec 13 2006, 05:30 AM, said:

Oh wow. These are absolutely amazing! Many are completely unique too. The land take of some of these is astonishing. My favourite would have to be the quadruple trumpet junction!

The UK has nothing on these. This is debatably our most complicated interchange, known as as spaghetti junction: http://maps.google.c...&...mp;t=k&om=1

That's cool!  And even more cool when I think that the ramps are designed for people driving on the LEFT.  

Tracer, we don't see many trumpets down here at all because of our lack of toll roads.  

Some of those from MA are big-time space wasters, IMO.  

Here are some from the New Orleans area.  This is the east-bank approach to the Crescent City.  Keep in mind the top ramps are over 100 feet off the ground, and that long rectangular building under the bridges is the infamous Morial Convention Center:


This is the interchange between Airline and Causeway.  Neither are freeways at this point.  But keep in mind that this is a 3-level interchange:

[dtown]

^thats cool.

Heres I-69 at I-475 here in Flint, MI.
http://maps.google.c...&...mp;t=k&om=1

Heres my favorite exit in Flint, even though ive only used it like once or twice.(Also if you look to the left in that pic, you can see a big railroad yard, which is pretty cool from above)
http://maps.google.c...007007,0.021179

A cool one in downtown Detroit.
http://maps.google.c...&...mp;t=k&om=1

Another in Detroit.
http://maps.google.c...&...&iwloc=addr


PS, sorry about the links. I dont want to take the time to upload the maps to my Flickr.

[dgreco]

dtown, on Dec 13 2006, 05:49 PM, said:

^thats cool.

Heres I-69 at I-475 here in Flint, MI.
http://maps.google.c...&...mp;t=k&om=1

Heres my favorite exit in Flint, even though ive only used it like once or twice.(Also if you look to the left in that pic, you can see a big railroad yard, which is pretty cool from above)
http://maps.google.c...007007,0.021179

A cool one in downtown Detroit.
http://maps.google.c...&...mp;t=k&om=1

Another in Detroit.
http://maps.google.c...&...&iwloc=addr


PS, sorry about the links. I dont want to take the time to upload the maps to my Flickr.

I really like the i-75 / rt10 interchange, it reminds me of a bunch of jumbled S's, kinda cool.

[tamias6]

Here is the US 131 and I 196 innetchange in Grand Rapids, MI

Google Map Image

The north and south bond lanes of US 131 innerwave with each other. So midway through the inerchange, oncoming traffic is to the right instead of the left. Got to take the entry and exit ramps slowly. They are very nerrow and there turning radii is sharper than a razor blade.

Edited by tamias6, 13 December 2006 - 05:24 PM.

[Rardy]

dtown, on Dec 13 2006, 04:49 PM, said:

Another in Detroit.
http://maps.google.c...&...&iwloc=addr

THAT is cool!

[Rardy]

This isn't really an interchange, but a roundabout.  This is the "South Traffic Circle" in Alexandria, LA.  It handles 40,000 vpd and has remarkably few accidents.  It's very efficient - the only drawback is the amount of land it requires.  It is bounded by 2-way frontage roads which do not have access to the circle:

Edited by Rardy, 14 December 2006 - 04:55 PM.

[richyb83]

Wow, really enjoy the interesting designs, thanks yall.

^I avoided the Alexandria round-about  last time I went thru there.

[Lance Winslow]

Well I think the I-10 thru San Antonio is a disaster maze trying to negotiate during traffic, but also the Mixing Bowl in Washington DC is outrageous. Then in SF, LA, Chicago, there are some ridiculous cluster mucks too? Who wins for the worst interchange? Still it is a good question and comment on how not to build a freeway?