Editing Single-point urban interchange (section)

===Inverted SPUI===
[[File:AS inverted SPUI.svg|thumb|Inverted SPUI where traffic [[driving on the left or right|drives on the right]]. Ramps are located between [[carriageway]]s.]]
A rarely built variant of the SPUI is the '''inverted SPUI''', in which the [[carriageway]]s of the free-flowing road are separated, with left on- and offramps running between the carriageways and coming to a single [[at-grade intersection]] with the cross street. This can be built less expensively than a standard SPUI by allowing for shorter, simpler bridges at the interchange. However, this inverts the usual convention of placing carriageway on- and offramps on the right side of the carriageway, instead placing them on the left side, usually considered the [[passing lane]].

====Notable examples====

* [[Interstate 290 (Illinois)|Interstate&nbsp;290]] in [[Oak Park, Illinois]], near [[Chicago]], at South Harlem Avenue ({{coord|41.873635|N|87.804505|W|}}) and at South Austin Boulevard ({{coord|41.871107|N|87.774331|W|}}).<ref>{{cite web |first= Anna |last= Lothson |title= IDOT to discuss I-290 interchanges at Austin, Harlem in Oak Park |date= June 7, 2012 |publisher= Wednesday Journal Inc. |url= http://www.oakpark.com/News/Articles/6-7-2012/IDOT-to-discuss-I_290-interchanges-at-Austin,-Harlem-in-Oak-Park/ |access-date= July 27, 2015 |archive-date= January 30, 2016 |archive-url= https://web.archive.org/web/20160130224750/http://www.oakpark.com/News/Articles/6-7-2012/IDOT-to-discuss-I_290-interchanges-at-Austin,-Harlem-in-Oak-Park/ |url-status= live }}</ref>
* [[Greensboro, North Carolina]], connecting [[Wendover Avenue (Greensboro)#West Wendover Avenue|West Wendover Avenue]] to South Holden Road ({{coord|36.064781|N|79.848098|W|}}).<ref name="Reid2004">{{cite web |first= Jonathan |last= Reid |publisher= [[Parsons Brinckerhoff]] |url= http://www.pbworld.com/pdfs/publications/monographs/unconventional_arterial_intersection_design.pdf |title= Unconventional Arterial Intersection Design, Management and Operations Strategies |date= July 2004 |access-date= September 9, 2012 |archive-date= November 15, 2015 |archive-url= https://web.archive.org/web/20151115040500/http://www.pbworld.com/pdfs/publications/monographs/unconventional_arterial_intersection_design.pdf |url-status= dead }}</ref><!-- P. 83-84 PDF P. 92-93 -->
* [[Interstate 244]] in [[Tulsa]], [[Oklahoma]], at Sheridan Road ({{coord|36.163289|N|95.904535|W|}}) and at Memorial Drive ({{coord|36.16234|N|95.886873|W|}}).
* [[U.S. Route 422 in Pennsylvania|U.S. Route&nbsp;422]] in [[Reading, Pennsylvania]], at [[U.S. Route 222 Business (Reading, Pennsylvania)|U.S. Route&nbsp;222 Business]] ({{coord|40.324345|N|75.933566|W|}}).
*[[Utah State Route 18|State Route&nbsp;18]] in [[St. George, Utah]], at Red Hills Parkway.
*[[Texas State Highway Spur 366|Woodall Rogers Freeway (TX Spur 366)]], in [[Dallas, Texas]] at Riverfront Boulevard, immediately before the [[Margaret Hunt Hill Bridge]] ({{coord|32.46547|N|96.48528|W|}}).

====Continuous green T (or seagull) hybrid====
There is also a variant of the inverted SPUI, which can be used when a side road ends at, rather than crossing, a free-flowing road. In this variant, one carriageway of the free-flowing road is grade-separated from the side road, as with a typical inverted SPUI, while the other carriageway of the free-flowing road is at-grade with but still separated from the side road, as found in a [[seagull intersection|continuous green T- (or seagull) intersection]].

There is one such interchange in [[Pultney Township, Belmont County, Ohio]], between [[Ohio State Route 7|State Route&nbsp;7]] (SR&nbsp;7) and [[Interstate 470 (Ohio–West Virginia)|Interstate&nbsp;470]] (I-470) at {{coord|40.047657|N|80.733542|W|}}. The ramps leading to and from I-470 run west of, but are not directly connected to, SR&nbsp;7; these ramps form the "side road" at this interchange. The southbound carriageway of SR&nbsp;7 bridges over the interchange, while its northbound carriageway remains at-grade. SR&nbsp;7's left on- and offramps run between its carriageways, meeting the I-470 ramps at an at-grade intersection. The I-470 ramps proceed to a [[trumpet interchange]] with I-470. I-470 itself bridges over both carriageways of SR&nbsp;7 a short distance north of the I-470/SR&nbsp;7 ramps' intersection. This design was likely chosen not for cost savings but because the northbound carriageway of SR&nbsp;7 is bordered by railroad tracks, commercial properties, and the [[Ohio River]] and because I-470 bridges the river just east of SR&nbsp;7—a more conventional interchange design was likely more difficult to achieve.

There is another such interchange in [[Millvale, Pennsylvania]], near [[Pittsburgh]], at the junction between [[Pennsylvania Route 28]] (PA&nbsp;28) and the [[Washington Crossing Bridge (Pittsburgh)|40th&nbsp;Street Bridge]]. The northbound carriageway of PA&nbsp;28 passes under the interchange, with lefthand ramps meeting at the bridge (the northbound entrance ramp does not provide direct access to PA&nbsp;28). The southbound carriageway of PA&nbsp;28 has a continuous green T-intersection with the bridge.<ref name=ppg>{{cite news|last=Schmitz|first=Jon|title=Whole new Route 28 beginning to emerge through construction|url=http://www.post-gazette.com/pg/11271/1178066-53.stm|date=September 28, 2011|access-date=August 4, 2015|work=[[Pittsburgh Post-Gazette]]|archive-date=October 6, 2011|archive-url=https://web.archive.org/web/20111006091526/http://www.post-gazette.com/pg/11271/1178066-53.stm|url-status=live}}</ref>

A similar interchange exists in [[Coal Grove, Ohio]], at the junction of [[U.S. Route 52 in Ohio|U.S. Route&nbsp;52]] (US&nbsp;52) with the [[Ben Williamson Memorial Bridge]] and the [[Simeon Willis Memorial Bridge]], which cross the [[Ohio River]] and lead to and from [[Ashland, Kentucky]], respectively. The eastbound carriageway of US&nbsp;52 passes under the interchange, with lefthand exit and entrance ramps to the bridges. The westbound carriageway of US&nbsp;52, which narrows to one throughlane, has a continuous green T-intersection with the bridges. The ramps cross each other [[wikt:at-grade|at-grade]], with a [[traffic light]]-controlled intersection.<ref>{{ cite web | url = http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/lawus0052r.pdf | author = Technical Services | title = Straight Line Diagrams: Lawrence County, US 52 | type = PDF | publisher = [[Ohio Department of Transportation]] | access-date = February 14, 2019 | archive-url = https://web.archive.org/web/20160320113505/http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/LAWUS0052R.pdf | archive-date = March 20, 2016 | url-status = live }}</ref>

An interchange, like that in Millvale, Pennsylvania, formerly existed at the junction of SR&nbsp;7 and [[Ohio State Route 822|SR&nbsp;822]] at the now-demolished [[Fort Steuben Bridge]] in [[Steubenville, Ohio]]. The northbound carriageway of SR&nbsp;7 passed under the bridge, with lefthand ramps meeting the bridge approach, while the southbound carriageway had a continuous green T-intersection with the bridge.<ref>{{ cite web | url = http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/jefsr0007r.pdf | author = Technical Services | title = Straight Line Diagrams: Jefferson County, SR 7 | type = PDF | publisher = [[Ohio Department of Transportation]] | access-date = August 4, 2015 | archive-url = https://web.archive.org/web/20131027062044/http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/jefsr0007r.pdf | archive-date = October 27, 2013 | url-status = live }}</ref>