AARoads Forum

National Boards => General Highway Talk => Topic started by: Streetman on August 20, 2023, 02:59:00 PM

Title: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: Streetman on August 20, 2023, 02:59:00 PM
There is an unusual interchange of I-91 and US-5 in W. Springfield, MA:
https://www.google.com/maps/@42.1361303,-72.6259138,17z/data=!5m1!1e4?entry=ttu
If it were built for an expressway going N-S it would be shaped like a figure 8, and this specific interchange was cited in an earlier topic:
https://www.aaroads.com/forum/index.php?topic=30753.msg2693622#msg2693622
but a figure 8 interchange seems to be something entirely different.
Advantages of this are no weaving on the expressway, taking up only a small extent of the arterial, and no traffic signals. Disadvantages are weaving on the ramps and additional signage needed on them.
Does this type of interchange exist anywhere else?
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: vdeane on August 20, 2023, 03:42:59 PM
I can't imagine too many existing since it has similar weaving issues as a cloverleaf on I-91 but with more bridges to minimize the footprint.  I'm not sure of an exact copy off the top of my head, but US 9 has something similar in Poughkeepsie, just with the ramps on the inside (https://www.google.com/maps/@41.7030174,-73.9375446,16.6z?entry=ttu).  The local MPO just did a study (https://www.dutchessny.gov/Departments/Transportation-Council/Poughkeepsie-9-44-55.htm) of potential redesigns because of the issues there.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: pderocco on August 20, 2023, 07:11:14 PM
I've always thought that interchange looked like a bowtie, but a bowtie is something else:

https://en.wikipedia.org/wiki/Bowtie_(road) (https://en.wikipedia.org/wiki/Bowtie_(road))

Here's another in Argentina:

https://goo.gl/maps/ZGEzrJ89YxVhc9B5A (https://goo.gl/maps/ZGEzrJ89YxVhc9B5A)

And just down the road is another even more complicated one:

https://goo.gl/maps/TXZqN2sdeaX9mNMg8 (https://goo.gl/maps/TXZqN2sdeaX9mNMg8)
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: Rothman on August 20, 2023, 08:26:46 PM
I was going to say bowtie, too, since the Poughkeepsie example has been informally called that for years.  But, alas, some other silly interchange template has hijacked the term.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: epzik8 on August 21, 2023, 08:03:15 AM
I wanted to say dumbbell, but it appears that's actually the name for an interchange with roundabouts.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: roadman65 on August 21, 2023, 08:06:07 AM
US 9 and 44 exchange in a similar fashion in Poughkeepsie, NY.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: Rothman on August 21, 2023, 08:44:54 AM
Quote from: roadman65 on August 21, 2023, 08:06:07 AM
US 9 and 44 exchange in a similar fashion in Poughkeepsie, NY.
As was said at least twice now already in the thread...

Say it again!
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: roadman65 on August 21, 2023, 08:51:47 AM
Quote from: Rothman on August 21, 2023, 08:44:54 AM
Quote from: roadman65 on August 21, 2023, 08:06:07 AM
US 9 and 44 exchange in a similar fashion in Poughkeepsie, NY.
As was said at least twice now already in the thread...

Say it again!

Okay I will.
US 9 and 44 in Poughkeepsie, NY. 😅
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: mgk920 on August 21, 2023, 10:18:45 AM
I-41/43/894 at 27th St in Milwaukee, WI is like that, but at a lesser intensity.
https://goo.gl/maps/RKsb8hm6A15QRJkZA

Mike
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: SectorZ on August 21, 2023, 10:24:13 AM
I don't know the name, but I think US 9 and US 44 in NY fits the criteria.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: JCinSummerfield on August 21, 2023, 12:38:37 PM
Quote from: epzik8 on August 21, 2023, 08:03:15 AM
I wanted to say dumbbell, but it appears that's actually the name for an interchange with roundabouts.

The one here in Monroe County where US-223 exits off from US-23 is called a dogbone.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: vdeane on August 21, 2023, 12:41:58 PM
Has anyone mentioned US 9 at US 44/NY 55 yet?  I feel like it's applicable to the thread... :sombrero:
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: mgk920 on August 21, 2023, 06:18:14 PM
Quote from: JCinSummerfield on August 21, 2023, 12:38:37 PM
Quote from: epzik8 on August 21, 2023, 08:03:15 AM
I wanted to say dumbbell, but it appears that's actually the name for an interchange with roundabouts.

The one here in Monroe County where US-223 exits off from US-23 is called a dogbone.

I've always heard of them being referred to as 'dogbone' roundabouts, too.

Mike
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: pderocco on August 21, 2023, 08:01:44 PM
I think dumbbell is the most appropriate name for the interchanges described by the Wikipedia article on bowties, given its shape.

But I guess no one can find a duplicate of the original one in Massachusetts, so that explains why it doesn't have an official name.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: Henry on August 21, 2023, 10:03:59 PM
Quote from: pderocco on August 21, 2023, 08:01:44 PM
I think dumbbell is the most appropriate name for the interchanges described by the Wikipedia article on bowties, given its shape.

But I guess no one can find a duplicate of the original one in Massachusetts, so that explains why it doesn't have an official name.
Yeah, I think we've found the most unique interchange in the world.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: amroad17 on August 21, 2023, 11:42:05 PM
Quote from: Henry on August 21, 2023, 10:03:59 PM
Quote from: pderocco on August 21, 2023, 08:01:44 PM
I think dumbbell is the most appropriate name for the interchanges described by the Wikipedia article on bowties, given its shape.

But I guess no one can find a duplicate of the original one in Massachusetts, so that explains why it doesn't have an official name.
Yeah, I think we've found the most unique interchange in the world.
This one as well as the US 35/OH 32 interchange in Jackson, OH.
https://goo.gl/maps/mA4kVFM8X78cYioJ9

To me, this should be a "bowtie"  interchange.  Any interchanges using roundabouts should be termed a "dogbone"  or "dumbbell" .
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: pderocco on August 22, 2023, 01:34:18 AM
Quote from: amroad17 on August 21, 2023, 11:42:05 PM
This one as well as the US 35/OH 32 interchange in Jackson, OH.
https://goo.gl/maps/mA4kVFM8X78cYioJ9

That should be called a pinwheel interchange.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: amroad17 on August 22, 2023, 01:46:07 AM
Quote from: pderocco on August 22, 2023, 01:34:18 AM
Quote from: amroad17 on August 21, 2023, 11:42:05 PM
This one as well as the US 35/OH 32 interchange in Jackson, OH.
https://goo.gl/maps/mA4kVFM8X78cYioJ9

That should be called a pinwheel interchange.
That is a great name for that particular, only one in the world, interchange.
Title: Re: Is there a name for this type of interchange shaped like the infinity symbol?
Post by: roadman65 on August 22, 2023, 04:57:53 AM
Quote from: amroad17 on August 22, 2023, 01:46:07 AM
Quote from: pderocco on August 22, 2023, 01:34:18 AM
Quote from: amroad17 on August 21, 2023, 11:42:05 PM
This one as well as the US 35/OH 32 interchange in Jackson, OH.
https://goo.gl/maps/mA4kVFM8X78cYioJ9

That should be called a pinwheel interchange.
That is a great name for that particular, only one in the world, interchange.

Interesting. All four ramps allow left turns.  Plus no real on ramp as all four are actual off ramps. Unique I must say.

https://www.google.com/maps/place/Myrtle+Beach,+SC/@33.7412991,-78.9528147,16.27z/data=!4m6!3m5!1s0x890068953b552101:0xbc0fb115b5d09618!8m2!3d33.6890603!4d-78.8866943!16zL20vMF9tM2s?entry=ttu
Then this one near Myrtle Beach, SC is another one far from duplicated elsewhere.