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National Boards => General Highway Talk => Topic started by: bugo on April 08, 2015, 07:08:29 AM

Title: Inverted SPUIs?
Post by: bugo on April 08, 2015, 07:08:29 AM
https://en.wikipedia.org/wiki/Single-point_urban_interchange#Inverted_SPUI

I call these X interchanges because the ramps form an X. The X interchange has left exits and left entrances for each ramp, and they all meet in the middle to form an at grade intersection. I-244, the Left Exit Expressway, has two. Wikipedia also mentions X interchanges in North Carolina and Illinois. What was the first X/inverted SPUI interchange built in the US? The Tulsa examples in the article were built in 1967.
Title: Re: Inverted SPUIs?
Post by: Stephane Dumas on April 08, 2015, 07:44:18 AM
I don't know what was the first but there another one in Philadelphia on I-76 at South Street Exit. http://goo.gl/maps/GylJK
Title: Re: Inverted SPUIs?
Post by: NE2 on April 08, 2015, 09:21:15 AM
Wacker at Monroe (no longer exists), built ca. 1950 (45 seconds into the video):

I don't know when Monroe became one-way eastbound.

The West Side Elevated Highway in NYC (1930s) had two interchanges like this, but spread out over several blocks.
Title: Re: Inverted SPUIs?
Post by: tradephoric on April 08, 2015, 09:37:25 AM
Inverted SPUI... another great progression killing interchange.  ;-)
Title: Re: Inverted SPUIs?
Post by: Mapmikey on April 08, 2015, 09:43:54 AM
Quote from: bugo on April 08, 2015, 07:08:29 AM
https://en.wikipedia.org/wiki/Single-point_urban_interchange#Inverted_SPUI

I call these X interchanges because the ramps form an X. The X interchange has left exits and left entrances for each ramp, and they all meet in the middle to form an at grade intersection. I-244, the Left Exit Expressway, has two. Wikipedia also mentions X interchanges in North Carolina and Illinois. What was the first X/inverted SPUI interchange built in the US? The Tulsa examples in the article were built in 1967.

The North Carolina example (I-73/74 at NC 42) opened about 1966.

Mapmikey
Title: Re: Inverted SPUIs?
Post by: Brandon on April 08, 2015, 09:44:55 AM
Quote from: NE2 on April 08, 2015, 09:21:15 AM
Wacker at Monroe (no longer exists), built ca. 1950 (45 seconds into the video):

I don't know when Monroe became one-way eastbound.

Sometime in the 1960s, IIRC.  Also, IIRC, there was one at Wacker and Randolph.  Both are now just one direction, one-way ramps.
Title: Re: Inverted SPUIs?
Post by: Brandon on April 08, 2015, 09:48:45 AM
Quote from: tradephoric on April 08, 2015, 09:37:25 AM
Inverted SPUI... another great progression killing interchange.  ;-)

Especially along the expressway itself.  The two along the Eisenhower Expressway (I-290) at Harlem (https://www.google.com/maps/@41.8734744,-87.8046363,238m/data=!3m1!1e3) (IL-43) and Austin (https://www.google.com/maps/@41.8709185,-87.7744635,237m/data=!3m1!1e3) are the cause of massive backups in during the rush and even off-peak times.  I believe both were built in the 1960s with that section of the Ike.
Title: Re: Inverted SPUIs?
Post by: NE2 on April 08, 2015, 10:02:22 AM
Quote from: tradephoric on April 08, 2015, 09:37:25 AM
Inverted SPUI... another great progression killing interchange.  ;-)
If an inverted SPUI kills your precious progression, so does every fucking four-way intersection.
Title: Re: Inverted SPUIs?
Post by: tradephoric on April 08, 2015, 10:19:47 AM
Quote from: NE2 on April 08, 2015, 10:02:22 AM
Quote from: tradephoric on April 08, 2015, 09:37:25 AM
Inverted SPUI... another great progression killing interchange.  ;-)
If an inverted SPUI kills your precious progression, so does every fucking four-way intersection.

Easy big fella.  You don't have to get so worked up over something as mundane as signal progression. 
Title: Re: Inverted SPUIs?
Post by: NE2 on April 08, 2015, 10:29:22 AM
I'm a dwarf, you insensitive clod.
Title: Re: Inverted SPUIs?
Post by: Brandon on April 08, 2015, 10:48:35 AM
Quote from: NE2 on April 08, 2015, 10:29:22 AM
I'm a dwarf, you insensitive clod.

OK, midget.  :-P
Title: Re: Inverted SPUIs?
Post by: Bickendan on April 08, 2015, 10:51:58 AM
Quote from: Brandon on April 08, 2015, 10:48:35 AM
Quote from: NE2 on April 08, 2015, 10:29:22 AM
I'm a dwarf, you insensitive clod.

OK, midget.  :-P
Be nice. It's either Gnome or Hobbit if you really want to go there...
Title: Re: Inverted SPUIs?
Post by: Alex on April 08, 2015, 12:32:52 PM
The one at US 422 and US 222 Business in Reading, PA (https://www.google.com/maps?ll=40.324426,-75.933364&spn=0.003734,0.008256&t=h&z=18) dates from 1963 per National Bridges.
Title: Re: Inverted SPUIs?
Post by: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.
Title: Re: Inverted SPUIs?
Post by: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.
Title: Re: Inverted SPUIs?
Post by: jeffandnicole on April 08, 2015, 12:43:19 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

Normal people weave in and out on the Schuykill at about 14 lane changes per mile, and don't notice the above.   :)
Title: Re: Inverted SPUIs?
Post by: Brandon on April 08, 2015, 12:44:58 PM
Quote from: jeffandnicole on April 08, 2015, 12:43:19 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

Normal people weave in and out on the Schuykill at about 14 lane changes per mile, and don't notice the above.   :)

So I noticed it when I drove it once back in September.  :-o
Title: Re: Inverted SPUIs?
Post by: myosh_tino on April 08, 2015, 03:10:15 PM
One of the options being considered for improving Lawrence Expressway in Sunnyvale, CA looks to be using inverted SPUIs at major cross streets...

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fpeninsulatransportation.org%2Fwp-content%2Fuploads%2F2013%2F12%2FScreen-Shot-2013-12-15-at-6.48.30-PM.png&hash=6827f19a84a9ded0528bdf7c41feef6cc2d67120)
Title: Re: Inverted SPUIs?
Post by: jakeroot on April 08, 2015, 05:44:55 PM
Quote from: myosh_tino on April 08, 2015, 03:10:15 PM
One of the options being considered for improving Lawrence Expressway in Sunnyvale, CA looks to be using inverted SPUIs at major cross streets...

I hope that's a joke.

EDIT: Oh good grief, it's real. To quote many others before me, "what is Caltrans smoking?"
Title: Re: Inverted SPUIs?
Post by: briantroutman on April 08, 2015, 06:09:40 PM
I suppose nearly all inverted (left enter/exit)diamonds could be considered "inverted SPUIs" . The four ramps will naturally meet at a single point unless the median is incredibly wide.

But do any inverted SPUIs preserve the continuous or semi-continuous right turns allowed by standard SPUIs?
Title: Re: Inverted SPUIs?
Post by: NE2 on April 08, 2015, 06:10:53 PM
Quote from: jakeroot on April 08, 2015, 05:44:55 PM
EDIT: Oh good grief, it's real. To quote many others before me, "what is Caltrans smoking?"
What does Caltrans have to do with it?
Title: Re: Inverted SPUIs?
Post by: jakeroot on April 08, 2015, 09:46:04 PM
Quote from: NE2 on April 08, 2015, 06:10:53 PM
Quote from: jakeroot on April 08, 2015, 05:44:55 PM
EDIT: Oh good grief, it's real. To quote many others before me, "what is Caltrans smoking?"

What does Caltrans have to do with it?

Uninformed Seattleite is uninformed.

What is Santa Clara County smoking!?
Title: Re: Inverted SPUIs?
Post by: mapman1071 on April 08, 2015, 09:50:19 PM
Arizona has one:
Loop 101 Agua Fria Freeway HOV +2 <6-9am 4-6pm> (Left) Exit 7A Maryland Avenue.
Title: Re: Inverted SPUIs?
Post by: myosh_tino on April 08, 2015, 10:53:31 PM
Quote from: jakeroot on April 08, 2015, 09:46:04 PM
Quote from: NE2 on April 08, 2015, 06:10:53 PM
Quote from: jakeroot on April 08, 2015, 05:44:55 PM
EDIT: Oh good grief, it's real. To quote many others before me, "what is Caltrans smoking?"

What does Caltrans have to do with it?

Uninformed Seattleite is uninformed.

What is Santa Clara County smoking!?

It kind of makes sense to me.

To build a typical diamond interchange would require the acquisition of a significant amount of land around each proposed interchange, most of which are business parks and retail shopping centers.  The use of the inverted SPUI and the elimination of one of the four travel lanes in each direction would cut down on the amount of additional land needed and thus keep costs down.
Title: Re: Inverted SPUIs?
Post by: bugo on April 08, 2015, 11:08:30 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

Sounds a lot like I-244.
Title: Re: Inverted SPUIs?
Post by: jakeroot on April 08, 2015, 11:49:50 PM
Quote from: myosh_tino on April 08, 2015, 10:53:31 PM
Quote from: jakeroot on April 08, 2015, 09:46:04 PM
Quote from: NE2 on April 08, 2015, 06:10:53 PM
Quote from: jakeroot on April 08, 2015, 05:44:55 PM
EDIT: Oh good grief, it's real. To quote many others before me, "what is Caltrans smoking?"

What does Caltrans have to do with it?

Uninformed Seattleite is uninformed.

What is Santa Clara County smoking!?

It kind of makes sense to me.

To build a typical diamond interchange would require the acquisition of a significant amount of land around each proposed interchange, most of which are business parks and retail shopping centers.  The use of the inverted SPUI and the elimination of one of the four travel lanes in each direction would cut down on the amount of additional land needed and thus keep costs down.

My concern is the resemblance to the Westside Highway, and my general distaste for left-side entrances and exits.

I'd rather see two through lanes in each direction with not as many junctions (ideally, half diamonds at Monroe and Arques, with frontage roads in between).
Title: Re: Inverted SPUIs?
Post by: bugo on April 08, 2015, 11:57:28 PM
This interchange is similar in concept (but was probably just stitched together from the time that I-35 didn't exist south of this interchange).
Title: Re: Inverted SPUIs?
Post by: myosh_tino on April 09, 2015, 01:21:32 AM
Quote from: jakeroot on April 08, 2015, 11:49:50 PM
My concern is the resemblance to the Westside Highway, and my general distaste for left-side entrances and exits.

I'd rather see two through lanes in each direction with not as many junctions (ideally, half diamonds at Monroe and Arques, with frontage roads in between).

Two lanes probably won't cut it but I think they could get away with 3 lanes.  While I agree that left exits and entrances on freeways are a bad idea, Lawrence Expwy is what I would consider a major arterial that has a posted speed limit of 50 MPH.  Keep in mind that the signals at the US 101 interchange and at Duane Ave will not be removed.

Actually, looking at the project website it looks like the county has decided to go with the inverted SPUIs plan but to depress the roadway some 30 feet so all crossing roadways and the train tracks would retain their current elevations.  The plan also calls for retaining the 8 travel lanes and add a 6 ft sidewalk and 6 ft bike lane on each side of the road so I guess there's going to be some pretty extensive property acquisition.

Project Website: http://www.sccgov.org/sites/rda/plans/Lawrence/Pages/legs.aspx
Title: Re: Inverted SPUIs?
Post by: JKRhodes on April 09, 2015, 07:13:36 AM
I suppose the HOV exits for 3rd St and 5th Ave on I-10 in Downtown Phoenix could be considered "Inverted Half-SPUIs," with the latter having an "inverted frontage road" through option to access 3rd Ave.
Title: Re: Inverted SPUIs?
Post by: ekt8750 on April 09, 2015, 02:12:58 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

The South St, 30th St/676, and Montgomery Av interchanges have to be the worst designed feats of engineering ever imagined. The bottlenecks at South St and 30th are the worst and for no reason other than some idiot that thought left side on ramps were a good idea.

You know it's bad when the best part of that freeway was the part built by the DRPA  :banghead:
Title: Re: Inverted SPUIs?
Post by: jeffandnicole on April 09, 2015, 02:40:51 PM
Quote from: ekt8750 on April 09, 2015, 02:12:58 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

The South St, 30th St/676, and Montgomery Av interchanges have to be the worst designed feats of engineering ever imagined. The bottlenecks at South St and 30th are the worst and for no reason other than some idiot that thought left side on ramps were a good idea.

You know it's bad when the best part of that freeway was the part built by the DRPA  :banghead:

And yet, has the lowest posted speed limit.
Title: Re: Inverted SPUIs?
Post by: ekt8750 on April 09, 2015, 03:10:15 PM
Quote from: jeffandnicole on April 09, 2015, 02:40:51 PM
Quote from: ekt8750 on April 09, 2015, 02:12:58 PM
Quote from: Brandon on April 08, 2015, 12:41:50 PM
Quote from: PHLBOS on April 08, 2015, 12:36:05 PM
I-76/South Street Interchange in Philadelphia (http://goo.gl/maps/dnzcq)

Originally built in the 1950s with the much of the on/off ramps reconstructed within the last decade as part of the South Street Bridge replacement project.

The Schuylkill Expressway has got to be one of the most diabolical open-air torture chambers ever designed by man.  Lanes that end and begin at random, with them exiting and entering on both sides - lose a right lane, and gain a left, wash, rinse, and repeat at the next interchange, then reverse it a half-mile later.

The South St, 30th St/676, and Montgomery Av interchanges have to be the worst designed feats of engineering ever imagined. The bottlenecks at South St and 30th are the worst and for no reason other than some idiot that thought left side on ramps were a good idea.

You know it's bad when the best part of that freeway was the part built by the DRPA  :banghead:

And yet, has the lowest posted speed limit.

And we all know why lol
Title: Re: Inverted SPUIs?
Post by: dfwmapper on April 10, 2015, 03:27:53 AM
What does US 75 and Parker Road in Plano, TX, count as? US 75 and the frontage road run at-grade, and Parker runs on an overpass, with no direct connection between the frontage road and Parker like your normally see in Texas. Left turns are SPUI-style with ramps connecting to/from the left side of the frontage road to Parker. Previously, there were 4 L shaped RI/RO ramps connecting Parker to the frontage road, but it was rebuilt into a SPUI in 2009/2010 because traffic was murder with all the commercial development along the frontage road in the early/mid 2000s (hello Costco). The old ramp locations now serve right turns only.

http://goo.gl/maps/AXC5W
Title: Re: Inverted SPUIs?
Post by: JKRhodes on April 10, 2015, 07:36:09 AM
Quote from: dfwmapper on April 10, 2015, 03:27:53 AM
What does US 75 and Parker Road in Plano, TX, count as? US 75 and the frontage road run at-grade, and Parker runs on an overpass, with no direct connection between the frontage road and Parker like your normally see in Texas. Left turns are SPUI-style with ramps connecting to/from the left side of the frontage road to Parker. Previously, there were 4 L shaped RI/RO ramps connecting Parker to the frontage road, but it was rebuilt into a SPUI in 2009/2010 because traffic was murder with all the commercial development along the frontage road in the early/mid 2000s (hello Costco). The old ramp locations now serve right turns only.

http://goo.gl/maps/AXC5W

I'd call it Very Texas  :)... a SPUI with the advance u-turns and grade separated service roads.
Title: Re: Inverted SPUIs?
Post by: kphoger on April 10, 2015, 09:28:48 PM
Yep. Just a SPUI. Some turnarounds thrown in because Texas is awesome, some elongated right-turn slips for whatever reason, other than that it's just run of the mill.
Title: Re: Inverted SPUIs?
Post by: jakeroot on April 10, 2015, 11:26:20 PM
Quote from: kphoger on April 10, 2015, 09:28:48 PM
some elongated right-turn slips for whatever reason

At least two are because of the previous squished cloverleaf. Perhaps the other two were for symmetry.
Title: Re: Inverted SPUIs?
Post by: bugo on April 11, 2015, 12:35:59 AM
Both right turn offramps meet the cross street at a 90ish degree angle. Why don't they merge into the street? There is no reason to turn left at these intersections.
Title: Re: Inverted SPUIs?
Post by: jakeroot on April 11, 2015, 01:26:21 AM
Quote from: bugo on April 11, 2015, 12:35:59 AM
Both right turn offramps meet the cross street at a 90ish degree angle. Why don't they merge into the street? There is no reason to turn left at these intersections.

Functionally, it's like a speed bump. Meeting the cross street at a 90ish degree angle sort of forces a stop. I think they're ridiculous, FWIW, but I understand the purpose.

But like I said before, those ramps are from the previous interchange.
Title: Re: Inverted SPUIs?
Post by: Otto Yamamoto on April 11, 2015, 02:14:29 PM
NY 9A at NY 117, unsure of the date that was built, this has the bonus of the Taconic State Parkway running immediately adjacent, so northbound NY 9A and the southbound Taconic pass under the same bridge.