Coolest Interchanges

[Stephane Dumas]

Here one cool interchange from Down Under in Australia where M4(Western Motorway) meet the Western Sydney Orbital http://goo.gl/maps/zyv6i  A deformed stack with a diamond interchange so close.

[LA_MetroMan]

Does anyone think the interchange of the Hollywood Freeway and the Harbor/Pasadena Freeway is cool or notable? I do, but I fear I may be the only one. 

you mean the Four-Level?  that's nothing; it's just the first stack interchange on the planet.

No offense my friend, but just because it was the first certainly doesn't belittle the fact that it is one cool interchange. When it first opened and you were going slow enough on the 101E, you could actually look down and see all levels, quite a site before the acre-gobbling new 300' sight distance interchanges.

[Alps]

Does anyone think the interchange of the Hollywood Freeway and the Harbor/Pasadena Freeway is cool or notable? I do, but I fear I may be the only one. 

you mean the Four-Level?  that's nothing; it's just the first stack interchange on the planet.

No offense my friend, but just because it was the first certainly doesn't belittle the fact that it is one cool interchange. When it first opened and you were going slow enough on the 101E, you could actually look down and see all levels, quite a site before the acre-gobbling new 300' sight distance interchanges.

Def. "Hyperbole":...

[jwolfer]

Okay, so this isn't *technically* an interchange... it doesn't make it any less cooler (in my eyes). I'm referring to something that only someone who grew up in Jersey could appreciate. It's the lowly jughandle, brought to its ultimate form. Yes, I mean...

The at-grade cloverleaf.

For those who aren't aware (and honestly, I'm pretty sure you all are):

http://goo.gl/maps/4wteQ

I HATE jughandles... I grew up in Ocean County and have driven thru this intersection many times.  In my opinion I would rather double left turn lanes all around.

[Alps]

Okay, so this isn't *technically* an interchange... it doesn't make it any less cooler (in my eyes). I'm referring to something that only someone who grew up in Jersey could appreciate. It's the lowly jughandle, brought to its ultimate form. Yes, I mean...

The at-grade cloverleaf.

For those who aren't aware (and honestly, I'm pretty sure you all are):

http://goo.gl/maps/4wteQ

I HATE jughandles... I grew up in Ocean County and have driven thru this intersection many times.  In my opinion I would rather double left turn lanes all around.

In order to do that, you need to have added signal phases, which decreases your green time on each approach. In order to then feed the same amount of traffic through, you need added lanes. Having more conflict points at the intersection and where the added lanes end leads to more accidents.

[Compulov]

I HATE jughandles... I grew up in Ocean County and have driven thru this intersection many times.  In my opinion I would rather double left turn lanes all around.

In order to do that, you need to have added signal phases, which decreases your green time on each approach. In order to then feed the same amount of traffic through, you need added lanes. Having more conflict points at the intersection and where the added lanes end leads to more accidents.

Wouldn't the fact that it's all right-hand turns and merges also reduce the severity of potential collisions? That is, more same-direction/sideswipe accidents and less t-bone and head-on collisions. Similar, I guess, to replacing a left turn at a 4-way intersection with a roundabout.

Growing up in Jersey, I don't have a problem with jughandles... I just hate roads where left turns are inconsistent, so unless you have a map or a gps (or know the area), you never know what lane you need to be in to make a left. Hooper and Bay are actually pretty good examples of inconsistent design in NJ.

[tradephoric]

Wouldn't the fact that it's all right-hand turns and merges also reduce the severity of potential collisions? That is, more same-direction/sideswipe accidents and less t-bone and head-on collisions. Similar, I guess, to replacing a left turn at a 4-way intersection with a roundabout.

Synthesis of the Median U-Turn Intersection Treatment, Safety, and Operational Benefits (FHWA-HRT-07-033) study states a 30% reduction in injury accidents compared to a conventional intersection (also, a 16% reduction in total accidents).  A study by North Carolina State University states a 63% reduction in injury accidents when comparing a Superstreet to a conventional intersection. 

[johndoe]

Stumbled across this one that I thought you might find interesting.  Aesthetically pleasing but I bet the weaving areas are nasty!
http://goo.gl/maps/ljqGv

And an offset SPUI, which I think has been discussed here before.
http://goo.gl/maps/VWazr

[intelati49]

Stumbled across this one that I thought you might find interesting.  Aesthetically pleasing but I bet the weaving areas are nasty!
http://goo.gl/maps/ljqGv

And an offset SPUI, which I think has been discussed here before.
http://goo.gl/maps/VWazr

Those are... ...interesting to say the least...

[Compulov]

Stumbled across this one that I thought you might find interesting.  Aesthetically pleasing but I bet the weaving areas are nasty!
http://goo.gl/maps/ljqGv

Wow... does that even have a name? If not, I herby declare that a "bowtie interchange".

And an offset SPUI, which I think has been discussed here before.
http://goo.gl/maps/VWazr

While that looks cool... I don't get it. I'm assuming there was a standard diamond there at one point (judging by the landscaping). Why couldn't they convert it to a regular SPUI? It looks like they had the room to build new ramps, was it easier/cheaper to build the crossover ramps than to expand the existing overpass to make the SPUI fit?

[Alps]

Stumbled across this one that I thought you might find interesting.  Aesthetically pleasing but I bet the weaving areas are nasty!
http://goo.gl/maps/ljqGv

Wow... does that even have a name? If not, I herby declare that a "bowtie interchange".

That's exactly what it's called. US 9/US 44-NY 55 is the one I'm familiar with.

[johndoe]

While that looks cool... I don't get it. I'm assuming there was a standard diamond there at one point (judging by the landscaping). Why couldn't they convert it to a regular SPUI? It looks like they had the room to build new ramps, was it easier/cheaper to build the crossover ramps than to expand the existing overpass to make the SPUI fit?

Well I don't know the history of the area but I can take a few guesses.  Here's a picture from 1991.

On EarthExplorer the OSPI was there in 2002.  So I'm guessing it went straight from an overpass to that design.  (Notice the east frontage road got pushed out)  My guesses on reasons they might have used this instead of normal SPUI:

1. They could utilize the existing bridge for "Alameda"
2. Better spacing between the three signals by pushing the interchange east
3. More efficient timing than normal SPUI (less clearance interval...lower cycle lengths...easier to coordinate)
4. More bike/ped friendly

[Michael]

I looked at the SPUI in Historic Aerials since I thought there was a diamond there at one time too, but johndoe beat me to posting.  I looked in Street View as well, and my theory is that it was shifted to provide more space between the SPUI and South Potamac Street to the west.  I don't understand why though, since the intersection of Abilene Street is just as close to the SPUI as South Potamac Street would have been, and based on the number of lanes, that side of the SPUI is busier.

[brownpelican]

The Carrollton Interchange in New Orleans (I-10/Carrollton Avenue/Airline Highway-Tulane Ave):

http://goo.gl/maps/pz54m

[Mark68]

I looked at the SPUI in Historic Aerials since I thought there was a diamond there at one time too, but johndoe beat me to posting.  I looked in Street View as well, and my theory is that it was shifted to provide more space between the SPUI and South Potamac Street to the west.  I don't understand why though, since the intersection of Abilene Street is just as close to the SPUI as South Potamac Street would have been, and based on the number of lanes, that side of the SPUI is busier.

I actually live near that interchange, and what you might not be able to tell is that Abilene Street was rerouted farther east to make room for the interchange and its approaches on Alameda. The new routing of Abilene St follows the contours of the edge of the parking lot for the mall (bottom right corner) and follows a similar contour north of Alameda. My guess is because there was less displacement of the buildings east of I-225 than there would have been west of the highway. Probably doesn't matter in the long run, as traffic is still bad, and 225 is going to be widened again for additional lanes + light rail.

[LA_MetroMan]

Calif state 57 at I-10 and Caif State 71, a stunning work of concrete and style, and damn fun to drive.

Truly motion in poetry.

[LA_MetroMan]

Never been there, but this one must've been fun to engineer.

http://www.flickr.com/photos/hgrpix/8361530109

[agentsteel53]

Never been there, but this one must've been fun to engineer.

http://www.flickr.com/photos/hgrpix/8361530109

where is that?  all I can tell is that it's a toll connection

[deathtopumpkins]

http://goo.gl/maps/TrL7A

Indiana Toll Road (I-90) at the north end of I-65 in Gary, IN.

[vdeane]

That is one interesting toll setup.

[Brandon]

http://goo.gl/maps/TrL7A

Indiana Toll Road (I-90) at the north end of I-65 in Gary, IN.

Attaching the end of an interstate to a pre-existing interchange for Dunes Highway (US-12/20).

[1995hoo]

http://goo.gl/maps/TrL7A

Indiana Toll Road (I-90) at the north end of I-65 in Gary, IN.

Amusing how Google Maps helpfully points out that the Indiana Toll Road is a toll road.

[deathtopumpkins]

http://goo.gl/maps/TrL7A

Indiana Toll Road (I-90) at the north end of I-65 in Gary, IN.

Amusing how Google Maps helpfully points out that the Indiana Toll Road is a toll road.

I agree it is amusing, but to be fair there are are toll roads which have free portions that are still considered part of the "toll road", like the Massachusetts Turnpike west of exit 6 (though you still take a ticket), in Newton, and around the Allston and Ted Williams tolls. Plus there are roads named "Turnpike" that aren't even tolled, like Newburyport Turnpike (US 1 between Danvers and Newburypot, MA), so the labeling can still be helpful to let you know whether you have to pay a toll or not on that stretch.

And it's also amusing that it's labeled "Indiana Toll Rd". Good old automatic abbreviations.

[1995hoo]

All good points. We have a couple of arterials here named "Turnpike" or "Pike" with no toll.

The Delaware Turnpike comes to mind as one that's signed as a toll road (at its northern end) when really only the one tiny piece that crosses the Maryland state line is tolled.

[vdeane]

like the Massachusetts Turnpike west of exit 6 (though you still take a ticket), in Newton, and around the Allston and Ted Williams tolls.

To be fair, it's only free to passenger cars; all others still pay a toll.