Interchanges

[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.gov/documents/MDOT_M-8..._1_155180_7.pdf

[richyb83]

Great topic ; Thanks Rardy for those interesting interchange pics.

thanks for posting that too dtown.

[dimebag1980]

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

[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.

[dgreco]

a providence interchange.

[Dozer]

a providence interchange.

[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.com/maps?f=q&hl=en&...mp;t=k&om=1

[dgreco]

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.com/maps?f=q&hl=en&...mp;t=k&om=1

[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]

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.com/maps?f=q&hl=en&...mp;t=k&om=1

[dtown]

^thats cool.

Heres I-69 at I-475 here in Flint, MI.

http://maps.google.com/maps?f=q&hl=en&...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.com/maps?f=q&hl=en&...007007,0.021179

A cool one in downtown Detroit.

http://maps.google.com/maps?f=q&hl=en&...mp;t=k&om=1

Another in Detroit.

http://maps.google.com/maps?f=q&hl=en&...&iwloc=addr

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

[dgreco]

^thats cool.

Heres I-69 at I-475 here in Flint, MI.

http://maps.google.com/maps?f=q&hl=en&...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.com/maps?f=q&hl=en&...007007,0.021179

A cool one in downtown Detroit.

http://maps.google.com/maps?f=q&hl=en&...mp;t=k&om=1

Another in Detroit.

http://maps.google.com/maps?f=q&hl=en&...&iwloc=addr

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

[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.

[Rardy]

Another in Detroit.

http://maps.google.com/maps?f=q&hl=en&...&iwloc=addr

[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:

[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?

[dgreco]

HI 201

HI 1

[Rardy]

How not to build an interchange? Try I-110 in Baton Rouge:

4 left lane exit and entrance ramps:

And a hairpin "S" curve:

[dgreco]

^ those 4 left lane exits look horrible, are their lots of accidents over there?

[FromCityToRural]

Texas' interchanges aren't so much bad as they are badly marked. In California, we had the luxury of having the interchanges clearly marked miles before. Here, you typically have half a mile, and usually less, to get into the right lane for your interchange. It's harrowing trying to jam over at the last minute, and creates tons of hazardous lane changes at the last minute as folks scramble to maneuver. We've missed entire interchanges because of it. Even the smaller highways suffer, as highway intersections aren't usually marked beforehand, and you have to rely on figuring out a maze of small signs AT the intersection to know what's what. Again, it's frustrating, as you're invariably in the wrong lane, so you have to turn around and backtrack. As good a job as Texas has done with things like the overall network of state highways and the urban U-turn lanes, the apalling signage is a huge, huge letdown.

[Recchia]

Rhode Island has horrific interchanges overall. Left exits everywhere, including 2 major left exits off I-95 for other major highways (I-195 and Route 4) and sharp curves where the speed limit drops to 45 mph, with on and off ramps right at curves. I-95 through Providence and Pawtucket and I-195 from 95 to East Providence are accident nightmares. Luckily I-195 is being relocated to be straighter and I-95 at 195 is being straightened somewhat.