{{short description|Type of large road intersection}} {{Hatnote|This article reflects countries that drive on the right. For countries that drive on the left, reverse right and left.}} thumb|Sample continuous-flow intersection with typical lane variation, turn restrictions, and traffic light position [[File:Intersection continuous flow.jpg|thumb|A continuous flow intersection in West Valley City, Utah showing the layout and normal traffic flow in the southwest portion of the intersection.]] A '''continuous flow intersection''' ('''CFI'''), also called a '''crossover displaced left-turn''' ('''XDL''' or '''DLT'''), is an alternative design for an at-grade road junction. Vehicles attempting to turn across the opposing direction of traffic (left in right-hand drive jurisdictions; right in left-hand drive jurisdictions) cross before they enter the intersection. No left turn signal in the intersection is then necessary. Instead, vehicles traveling in both directions can proceed, including through vehicles and those turning right or left, when a generic traffic signal/stop sign permits.
Its design also is promoted as part of the Federal Highway Administration's Every Day Counts initiative which started in 2011.<ref>{{cite book |first1 = Bastian |last1 = Schroeder |first2 = Chris |last2 = Cunningham |first3 = Brian |last3 = Ray |first4 = Andy |last4 = Daleiden |first5 = Pete |last5 = Jenior |first6 = Julia |last6 = Knudsen |date = August 2014 |title = Diverging Diamond Interchange Informational Guide |url = https://rosap.ntl.bts.gov/view/dot/29474/dot_29474_DS1.pdf?download-document-submit=Download |location = Washington, DC |publisher = Federal Highway Administration Office of Safety }}</ref>
== History == A fly-over designed CFI interchange (separated grade) was invented by Francisco Mier. An intersection (at-grade) variant followed. Over 40 have been implemented since 2000. Mier patented his design and required a fee to obtain a license to the design.<ref name="Hummer">{{cite web | url=http://www.urbanstreet.info/1st_symp_proceedings/Ec019_e3.pdf | title=Unconventional Left-Turn Alternatives for Urban and Suburban Arterials | access-date=13 June 2007 | last1=Hummer | first1=Joseph E. | last2= Reid | first2= Jonathan D. | publisher=Transportation Research Board | url-status=dead | archive-url=https://web.archive.org/web/20070930055756/http://www.urbanstreet.info/1st_symp_proceedings/Ec019_e3.pdf | archive-date=30 September 2007}}</ref> The patent expired in the United States on 15 October 2003.<ref>[http://portal.uspto.gov/external/portal/pair United States Patent and Trademark Office], {{patent||US|5049000|patent}}</ref>
This general configuration has appeared in different versions in various places, with the implementation of channelization in the United States since the 1950s, such as the Telegraph Road section of U.S. Route 24 in Michigan at Plymouth Road in Redford Charter Township, Michigan.<ref>Telegraph Road, Michigan {{coord|42.371267|N|83.275563|W}}</ref> which was removed in 2019.
== Usage == {| class="wikitable" |+List of places where a CFI is used !Country !State/Province !City !Roads !Opening date !Coordinates !Notes |- | rowspan="3" |Australia |Queensland |Gold Coast |Salerno Street, Bundall Road and Ashmore Road |December 2017 |{{Coord|-28.011815|153.411862|display=inline}} | |- |Victoria |Melbourne |Punt Road, Swan Street and Olympic Boulevard |September 2019 |{{Coord|-37.824601|144.988797|display=inline}} |<ref>{{Cite web |last=Tomazin |first=Farrah |date=2015-03-21 |title=Radical plan to ease Hoddle Street gridlock |url=https://www.theage.com.au/national/victoria/radical-plan-to-ease-hoddle-street-gridlock-20150321-1m4iyz.html |access-date=2024-10-18 |website=The Age |language=en}}</ref><ref>{{Cite web |last=Build |first=Victoria’s Big |date=2021-12-07 |title=Streamlining Hoddle Street |url=https://bigbuild.vic.gov.au/projects/roads/streamlining-hoddle-street |access-date=2025-11-25 |website=Victoria’s Big Build |language=en}}</ref> |- |New South Wales |Moore Park |Anzac Parade, Alison Road and Dacey Avenue |2017 | | |- |Canada |Prince Edward Island |Charlottetown |Charlottetown Perimeter Highway and St. Peters Road |November 29, 2020 |46.268692°N 63.114001°W |<ref>{{Cite web |last=Toolkit |first=Web Experience |date=2020-11-03 |title=Displaced Left Turn Intersection |url=https://www.princeedwardisland.ca/en/information/transportation-and-infrastructure/displaced-left-turn-intersection |access-date=2024-10-18 |website=www.princeedwardisland.ca}}</ref> |- |China |Guangdong |Shenzhen |{{ill|Caitian Road|zh|彩田路}} and Fuhua Road |October 7, 2017 |22.537588°N 114.062896°E |<ref>{{Cite web |date=19 October 2017 |title=【城市交通】深圳启用全国首个“移位左转”交通组织路口 |trans-title=(Urban transportation) The first displaced left-turn intersection in China begins operation in Shenzhen |url=https://www.its-china.org.cn/ds/2307a395a4.html |url-status=live |archive-url=https://web.archive.org/web/20251029202056/https://www.its-china.org.cn/ds/2307a395a4.html |archive-date=29 October 2025 |access-date=29 October 2025 |website=中国智能交通协会 |language=zh}}</ref> |- |Germany | |Hamburg |Breitenfelder Straße (Bundesstraße 5) and Tarpenbekstraße (Bundesstraße 433) | |53.590267°N 9.982989°E | |- | rowspan="3" |Mexico |Coahuila |Saltillo |Paseo de la Reforma and Periférico und Luis Echeverría | |25.42739°N 100.969859°W |Former configuration, now a directional interchange |- |Chihuahua |Juárez Municipality |Manuel Gómez Morin Bermúdez aund De La Industria | |31.70368°N 106.401998°W | |- |Nuevo León |Guadalupe Island |Between Chapultepec, Puesta del Sol and Av Eloy Cavazos | |25.661967°N 100.258747°W | |- |United Kingdom | |Swindon |A4311 road, Cricklade Road and Thamesdown Drive |2003 |51.601158562°N 1.7812545°W | |- | rowspan="40" |United States | rowspan="2" |New Jersey |Camden |New Jersey Route 168 at US Route 130 | | | |- |Audubon, New Jersey |New Jersey Route 168 at Nicholson Road | |39.894161°N 75.091435°W | |- |New York |Shirley | |1996 |40.826443°N 72.881042°W | |- | rowspan="2" |Maryland |Accokeek |Routes 210 and 228 |2000 |38.664126°N 77.016928°W | |- |Laurel |MD 200 and US 1 |November 7, 2014 |39.065800°N 76.881176°W | |- | rowspan="2" |Louisiana |Baton Rouge |Airline Highway and Siegen Lane |March 2006 |30.398914°N 91.054119°W |<ref name="Louisiana" /> |- |Lafayette |US 167 (Johnston St.) and Camellia Boulevard |2010 |30.193744°N 92.058622°W | |- | rowspan="11" |Utah |Taylorsville |Bangerter Highway and 5400 South (SR-173) | |40.652993°N 111.981339°W |No longer exists<ref name=":0">{{Cite web |title=Bangerter Highway Project Highlight |url=https://huntelectric.com/article/30/bangerter-highway-project-highlight |access-date=2024-10-18 |website=Hunt Electric |language=en}}</ref> |- | rowspan="7" |West Valley City |Bangerter Highway and 4700 South | |40.667596°N 111.981567°W |No longer exists |- |Bangerter Highway and 4100 South | |40.682132°N 111.981626°W | |- |Bangerter Highway and 3500 South (SR-171) |September 2007 |40.696629°N 111.980869°W | |- |Bangerter Highway and 3100 South | |40.703918°N 111.980076°W | |- |Bangerter Highway and 6200 South (Bennion Boulevard) | |40.638581°N 111.976637°W |No longer exists |- |5400 S (SR-173) and Redwood Road | |40.653176°N 111.938802°W | |- |6200 South (Bennion Boulevard) and Redwood Road | |40.638574°N 111.938824°W |<ref name=":1" /><ref>{{Cite AV media |url=https://www.youtube.com/watch?v=eKAONboIzao |title=DLT Case Study – Redwood Road at 6200 South in Taylorsville (Utah) |date=2014-07-31 |last=Federal Highway Administration USDOTFHWA |access-date=2024-10-18 |via=YouTube}}</ref> |- |Riverton |Bangerter Highway and 13400 South | |40.507803°N 111.982747°W |No longer exists |- |West Jordan |Bangerter Highway and 7000 South | |40.623983°N 111.976422°W |No longer exists<ref name=":0" /> |- |Orem |University Parkway and Sandhill Road |May 22, 2012 |40.275014°N 111.713445°W |<ref name="auto">{{Cite web |title=Internet Archive: Scheduled Maintenance |url=https://web.archive.org/sry |access-date=2024-10-18 |website=web.archive.org}}</ref> |- | rowspan="2" |Mississippi |Natchez |US 61 and Junkin Drive |January 2010 |31.528599°N 91.389213°W | |- |Oxford |Mississippi Highway 6 and West Jackson Avenue |April 29, 2015 | | |- | rowspan="4" |Colorado |Loveland |US 34 (Eisenhower Boulevard) and Madison Avenue | |40.407365°N 105.058764°W |<ref name="auto"/> |- |Durango |US 160 and US 550 | |37.268540°N 107.884992°W |<ref>{{Cite web |title=US 160/US 550 Durango Continuous Flow Intersection |url=https://www.codot.gov/projects/us160_us550durangocfi |website=CODOT.gov}}</ref> |- |Colorado Springs |Woodmen Road and Union Boulevard |December 2017 |38.933079°N 104.775202°W |<ref>{{Cite AV media |url=https://vimeo.com/245055910 |title=Woodmen Road Corridor CFI Intersection (long version) |language=en |access-date=2024-10-18 |via=vimeo.com}}</ref> |- |Wheat Ridge |Wadsworth Boulevard at 38th Avenue and 44th Avenue |December 9, 2025 |39°46'09.7"N 105°04'53.6"W |<ref>{{Cite web |date=December 9, 2025 |title=‘Intersection of the future’: Continuous flow intersections open in Wheat Ridge |url=https://kdvr.com/news/local/intersection-of-the-future-continuous-flow-intersections-open-in-wheat-ridge/}}</ref> |- |North Carolina |Charlotte |NC 16 to Mount Holly-Huntersville Road |October 18, 2019 |35.32566°N, 80.94523°W | |- | rowspan="5" |Texas |Cedar Park |RM 1431 and Ronald Reagan Boulevard/Parmer Lane |August 2, 2016 |30.534659°N 97.782645°W | |- |Pflugerville |Dessau Road and Pecan Street | |30.436611°N 97.613889°W | |- | rowspan="2" |San Marcos |Loop 82 (Aquarena Springs Drive) and I-35's southbound-to-northbound Texas U-turn | |29.893048°N 97.913367°W | |- |State Highway 80 (Hopkins Street), I-35's frontage roads and I-35's Texas U-turns | |29.882639°N 97.921915°W | |- |San Antonio |Bandera Road and Loop 1604 |April 28, 2019 |29.553655°N 98.667302°W |<ref>{{Cite web |last=Txdotsanantonio |date=April 26, 2019 |title=Go Ahead!: It's Here: SA's First DLT Intersection Opens This Weekend |url=https://txdotsanantonio.blogspot.com/2019/04/ready-san-antonio-we-appreciate-your.html |access-date=2024-10-18 |website=Go Ahead!}}</ref> |- |Georgia |Dawsonville |SR 400 and SR 53 |May 15, 2017 |34.363385°N 84.036474°W |<ref>{{Cite web |title=Continuous flow intersection now open in Dawson |url=https://www.gainesvilletimes.com/news/continuous-flow-intersection-now-open-in-dawson/ |access-date=2024-10-18 |website=www.gainesvilletimes.com}}</ref> |- | rowspan="3" |Indiana |Indianapolis |US 31 and Thompson Road |October 8, 2022 |39.693213°N 86.148812°W |<ref>{{Cite web | title=INDOT Opens State's First Displaced Left Turn |url= https://www.in.gov/indot/about-indot/Blog/indot-opens-states-first-displaced-left-turn/ |access-date=2024-11-22 |website=IN.gov|date= 24 February 2023 }}</ref> |- |Ohio Township (Warrick County) |IN 66 and Epworth Road |August 20, 2024 | 37.976790°N 87.441226°W |<ref>{{Cite web | date=2024-08-14 | title= Displaced left turn set to open at State Road 66 and Epworth |url= https://www.tristatehomepage.com/news/displaced-left-turn-set-to-open-at-state-road-66-and-epworth/ |access-date=2024-11-22 |website=TristateHomepage.com}}</ref> |- |Evansville |IN 66 and Stockwell Road |June 18, 2025 | 37.976675°N 87.502408°W |Hybrid design with one displaced left turn and a Michigan left as the other turn. <ref>{{Cite web | date=2025-06-16 | title= Official schedule for Lloyd4U work released |url= https://www.14news.com/2025/06/16/official-schedule-lloyd4u-work-released/ |access-date=2025-07-11 |website=WFIE}}</ref> |- | rowspan="2" |Ohio |Anderson Township |Beechmont Avenue (State Route 125) and Five Mile Road |May 19, 2017 |39°4′22″N 84°21′7″W |<ref>{{Cite web |date=2017-05-08 |title=How does the new Anderson Twp intersection work? |url=https://www.wcpo.com/news/local-news/hamilton-county/anderson-township/new-continuous-flow-intersection-beechmont-five-mile-in-anderson-township-opening-may-19 |access-date=2024-10-18 |website=WCPO 9 Cincinnati |language=en}}</ref> |- |Miami Township (Montgomery County) |SR 741 and Miamisburg-Springboro Road/Austin Boulevard |2009 |39.596709°N 84.229029°W |<ref>{{Cite web |date=2009-01-02 |title=Austin Pike |url=https://www.dot.state.oh.us/districts/D07/Projects/Pages/AustinPike.aspx |access-date=2024-10-18 |archive-url=https://web.archive.org/web/20090102062830/https://www.dot.state.oh.us/districts/D07/Projects/Pages/AustinPike.aspx |archive-date=2009-01-02 }}</ref> |- |Virginia |Norfolk |Military Highway onto Northampton Boulevard and Princess Anne Road |July 28, 2018 |36.874804°N 76.210739°W | |- |Florida |Fort Myers |State Road 82 to Daniels Parkway (west) and Gunnery Road (east) |July 9, 2019 |26.581661°N 81.713761°W |<ref>{{Cite web |date=2019-07-09 |title=New Continuous Flow Intersection now open in Lehigh Acres |url=https://www.fox4now.com/news/local-news/continuous-flow-intersection-now-open-in-lee-county |access-date=2024-10-18 |website=FOX 4 News Fort Myers WFTX |language=en}}</ref> |- |Kansas |Olathe |Old 56 Highway to Lone Elm Road |June 2021 | |- |Missouri |Fenton |Highway 30 and Summit Drive/Gravois Bluffs Boulevard |October 2007 |38.504276°N 90.456995°W |<ref>{{Cite web |date=2007-09-27 |title=Continuous Flow Intersections2 |url=http://www.modot.org/stlouis/links/ContinuousFlowIntersections2.htm |access-date=2024-10-18 |archive-url=https://web.archive.org/web/20070927223552/http://www.modot.org/stlouis/links/ContinuousFlowIntersections2.htm |archive-date=2007-09-27 }}</ref> |} [[File:Driving trough the Coninuous-Flow Intersection Utah SR-154 Bangerter Hwy at 4100 South 2013-07.ogg|thumb|Driving through a continuous flow intersection on Utah State Route 154 (Bangerter Highway) at 4100 South in summer 2013.]] [[File:2006 11 14 - 228@210 - WB CFI 1.JPG|thumb|A continuous flow intersection between Maryland Route 210 and Maryland Route 228 in Accokeek, Maryland.]] thumb|Sketch and traffic light sequence of a four-way intersection with displaced left turns on two of the legs.{{GeoGroup|level=0}}
== Operational details == Part of the delay at a typical high-volume right-hand traffic intersection is to accommodate left-turns; through-traffic must wait for the traffic turning left because it crosses the path of the through traffic. The continuous flow intersection moves the left-turn conflict out of the intersection and synchronizes it with the signal cycle of the intersecting road.
In the adjacent diagram, while the left/right traffic flows through the main intersection, the left-turn traffic crosses to the opposite side of the oncoming traffic a few hundred feet away. Doing this removes the crossing conflict. When the north/south through traffic is allowed through the main intersection, the north/south left-turn lanes are also allowed through the intersections as their paths are no longer crossing. All traffic flow is controlled by traffic signals as at a regular intersection.
The Louisiana DOTD article on the Baton Rouge CFI includes a particularly informative diagram of that intersection.<ref name="Louisiana">{{cite web |last=Ruiz de Chavez |first=Lindsay |date=2006-03-21 |title=First 'continuous-flow' intersection in the state opens on Airline today |url=http://www.dotd.louisiana.gov/pressreleases/Release.aspx?key=627 |url-status=dead |archive-url=https://web.archive.org/web/20100527101018/http://www.dotd.louisiana.gov/pressreleases/Release.aspx?key=627 |archive-date=2010-05-27 |access-date=4 August 2018 |publisher=Louisiana Department of Transportation & Development}}</ref>
To reduce confusion regarding the left-turn lane, the left-turn lane and the straight-through lanes are usually separated by a concrete barrier or traffic island. This diagram shows the straight-through lanes offset by one lane through the intersection and are guided by lines painted through the intersection. But this is just a sample configuration; the lanes may be offset by more lanes or none at all.
Nonetheless, due to the provision of traffic between two directions of opposing traffic, some motorists tend to maintain an ongoing criticism of the intersection. Additionally, as in the case of the half-CFI in Accokeek, the offset left-turn traffic reenters the main traffic stream via a half-signal, requiring motorists to merge from a stop condition onto the higher-speed mainline. Motorists sometimes cite discomfort due to the speed differential, a known cause of accidents, though conflicts can be reduced through the provision of an adequate acceleration lane and merge area. The Accokeek, Maryland CFI also has notable inequalities in traffic flow depending upon the direction of travel.
This type of intersection can require a significant amount of right-of-way to implement (dependent upon the configuration), which is why the technique is not frequently used in urban areas. However, the amount of right-of-way necessary for construction and final operation is still typically less than that of an interchange. Additionally, as there is no grade separation involved, costs are considerably less than that of an interchange alternative.
== Case studies == The redesign of the Redwood Road/6200 South intersection in Taylorsville, Utah cut emissions of carbon dioxide by 19 tons (17 tonnes) per year.<ref name=":1">FHWA: [https://www.youtube.com/watch?v=eKAONboIzao DLT Case Study – Redwood Road at 6200 South in Taylorsville (Utah)], published July 31, 2014</ref> Compared to the previous design, the redesign of the Bangerter Highway/3500 South intersection saves {{frac|3|1|2}} minutes of travel time per vehicle and {{convert|800,000|USgal|L|abbr=off|sp=us}} of fuel per year, and has 60% fewer accidents nearby; it also cost $20 million to $40 million less in construction costs than a grade-separated alternative.<ref>FHWA: [https://www.youtube.com/watch?v=o5-U_TgEtJA DLT Case Study – Bangerter Highway in Salt Lake County (Utah)], published July 31, 2014</ref>
== Parallel-flow intersection == A '''parallel-flow intersection''' ('''PFI''') is a variant similar to the CFI, patented in 2006.<ref>{{cite patent | country = US | number = 7135989 B2 | title = Parallel flow vehicle turn system for traffic intersections | status = patent | inventor = Gregory Fife Parsons | assign1 = Gregory Fife Parsons | gdate = 2006-11-14 | pridate = 2004-09-27| fdate = 2004-09-27 }}</ref> It arranges the left-turning traffic in a different manner; it is not displaced, instead turning left closer to the intersection onto a parallel roadway, to the left of oncoming traffic.<ref>Federal Highway Administration: [https://www.fhwa.dot.gov/publications/research/safety/09060/006.cfm ''Alternative Intersections/Interchanges: Informational Report (AIIR)''], Publication Number: ''FHWA-HRT-09-060'', April 2010</ref> This was first used in New Jersey at the junction of New Jersey Route 168 and US Highway 130, between Haddon Township and Camden ({{coord|39.90412|N|75.095812|W}}).
== See also == {{columns-list|colwidth=20em| * Junction (road) * Advanced stop line * Bowtie * Box junction * Hook turn * Jughandle * Michigan left * Quadrant roadway intersection * Roundabout * Seagull intersection * Slip lane * Staggered junction * Superstreet * Texas T * Texas U-turn * Turnaround (road) }}
== References == {{Reflist|30em}}
== External links == * Federal Highway Administration, [http://www.tfhrc.gov/safety/pubs/04091/10.htm#1023 Alternative Intersection Treatments - CFI] * University of Maryland, [https://web.archive.org/web/20110720090118/http://attap.umd.edu/UAID_ags.php?UAIDType=5&iFeature=2 ATTAP] - Animation of a CFI (QuickTime required). Additional information may be accessed via the links on the left side. *: <small>''Note that due to the relatively recent installation of the CFI in Baton Rouge, West Valley, UT, and Fenton, MO, some images may not show the existing conditions.''</small> * [https://web.archive.org/web/20060623050623/http://deseretnews.com/dn/view/0,1249,610152168,00.html Deseret News story about CFI] * [http://www.ksl.com/?nid=148&sid=109039 KSL News story about CFI] * [https://web.archive.org/web/20050930182940/http://www.tfhrc.gov/pubrds/05jan/03.htm U.S. Department of Transportation] * [http://www.natchezdemocrat.com/news/2009/dec/04/continuous-flow-intersection-opens/ CFI open in Natchez, MS] * Seonyeong Cheong, Saed Rahwanji and Gang-Len Chang: [https://web.archive.org/web/20131230022522/http://attap.umd.edu/bbs/data/publications/Seonyeong_IEEE08_1.pdf Comparison of Three Unconventional Arterial Intersection Designs: CFI, PFI and Upstream Signalized Crossover], ATTAP, University of Maryland, 3 June 2008 * [http://www.virginiadot.org/FHWA-SA-14-068DLTInformationalGuide.pdf ''DISPLACED LEFT TURN INTERSECTION Informational Guide''], Federal Highway Administration, Publication No. FHWA-SA-14-068, August 2014
{{Road junction types}}
{{DEFAULTSORT:Continuous-Flow Intersection}} Category:Road junction types Category:Articles containing video clips