Quadrant roadway intersection

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A single-quadrant roadway intersection. Green traffic arrives from the south and wants to turn left/west. Blue traffic arrives from the east and want to turn left/south. Note how left turns are not available at the main intersection.

A quadrant roadway intersection adds an additional "quadrant roadway" between two legs of an intersection. This roadway adds two three-way intersections in addition to the original four-way intersection moving all left turns (in right-hand traffic countries) or right turns (in left-hand traffic countries) from the main intersection. The design is intended to improve traffic flow by reducing signal timing phases from four to two in the main intersection. The design is intended for intersections where large artery routes meet in an area of dense development and high pedestrian volume.[1][2]

Proponents also point to a reduction in places where accidents could occur from vehicles potentially crossing paths as well as a low development cost compared to roundabouts or the more complex single-point urban interchange designs.[1][3][4] Opponents point to the increase in points where accidents could occur with merging traffic as well as the non-traditional nature of the design which has the potential to confuse drivers. Opponents also rebut low cost claims pointing to right-of-way and construction costs of the quadrant road.[1][3]

A related structure known as a jughandle accomplishes similar traffic movement from a more compact shape.

Double-quadrant intersections[]

Single-quadrant intersections (pictured above) feature a single quadrant road.

A double-quadrant intersection (or two-quadrant intersection) adds a second quadrant road placed opposite another.[5][6][7]

Examples of quadrant intersections[]

Germany[]

Single-quadrant intersections[]

  • Dortmund, North Rhine-Westphalia – (map) Ardey Straße/Hagener Straße and Stockumer Straße

United States[]

Single-quadrant intersections[]

  • Lansing, Michigan – (map) Martin Luther King Avenue at Grand River Avenue (Business Loop Interstate 96)
  • Fairfield, Ohio – (map) State Route 4 at State Route 4 Bypass (4B) and Ross Road. Diversion Road is used as the quadrant road.
  • Aldie, Virginia – (map) John Mosby Highway (US Route 50) and James Monroe Highway (US Route 15). Howsers Branch Drive is used as the quadrant road.
  • Mill Creek, Washington – (map) Washington State Route 527 and Washington State Route 96 via 16th Avenue SE (partial)

Double-quadrant intersections[]

Proposed[]

  • Cary, North Carolina – Cary Parkway and High House Road (both single- and double-quadrant proposed, but rejected, citing the local preference for a "traditional intersection layout")[8]

Quadrant interchanges[]

German one-quadrant interchange (or Verkehrsknoten teilplangleich)

An interchange variant of the quadrant roadway intersection links grade-separated roads, generally a faster road with denser traffic, to a less traveled, slower road, via the quadrant road. This design is referred to as a one-quadrant interchange[9] or as a single-loop intersection.[4] This type of junction is common in Germany, where it is called a "partial at-grade intersection" (German: Teilplangleicher Verkehrsknoten).[10] A so-called two-quadrant interchange also exists, which adds a second quadrant road (although the term "two-quadrant interchange" could be applied to any grade-separated junction in which there are ramps in two quadrants).[11]

Examples of quadrant interchanges[]

Canada[]

One-quadrant interchanges[]

One-quadrant interchanges (called single-loop intersections) are found in the Greater Toronto Area in Ontario:

  • Mississauga – (map) Dundas Street and Cawthra Road
  • Oshawa – (map) Bloor Street and Stevenson Road
  • Single-loop intersections are used frequently in the Thornhill community, notably along Highway 7:
    • Markham – (map) at Bayview Street
    • Markham – (map) at Yonge Street
    • Vaughan – (map) at Bathurst Street
    • Vaughan – (map) at Langstaff Road and Dufferin Street

Japan[]

Two-quadrant interchanges[]
Both interchange types[]
  • National Route 4 features numerous one- and two-quadrant interchanges along its length.

United States[]

One-quadrant interchanges[]
  • Wallingford, Connecticut – (map) Colony Road (US 5) and Church Street (Connecticut Route 68)
  • Owings Mills, Maryland – (map) Maryland Route 140 (Reisterstown Road) and Owings Mills Boulevard (MD 940)
  • Billings, Montana – (map) Hilltop Road and Lake Elmo Drive
  • Clarks, Nebraska - (map) US 30 at Nebraska Highway 92. Link 61D is the connector road.
  • Kernersville, North Carolina – (map) NC 150 (Macy Grove Road) and Mountain Street
  • Akron, Ohio – (map) Exchange Street and Wolf Ledges Parkway. (The quadrant roadway has its own name, Arc Drive, but has no driveways or addresses and serves solely as the quadrant roadway.)
  • Smyrna, Tennessee – (map) Lee Victory Parkway (State Route 102) and Old Nashville Highway
Two-quadrant interchanges[]
Both interchange types[]
  • Mississippi, Alabama and Tennessee - The Natchez Trace Parkway features numerous one- and two-quadrant interchanges along its length.
  • North Carolina and Virginia - The Blue Ridge Parkway features numerous one- and two-quadrant interchanges along its length.

References[]

  1. ^ Jump up to: a b c Turner-Fairbank Highway Research Center (August 2004). "Signalized Intersections: Informational Guide". ALTERNATIVE INTERSECTION TREATMENTS. United States Department of Transportation. Retrieved 3 January 2010.
  2. ^ Cooke, Jordan (Mar 24, 2009). "Left turns left out of road redesign". Cary News. Archived from the original on April 10, 2009. Retrieved 3 January 2010.
  3. ^ Jump up to: a b Hummer, Joseph E. (May 14, 2003). "Moving More Cars Through the Same Space Using Unconventional Intersection Designs" (PDF). NCDOT Traffic Engineering Conference. North Carolina State University. Retrieved 3 January 2010.
  4. ^ Jump up to: a b "Quadrant Roadway Intersection vs. Traditional Intersection" (PDF). Community Planning Assn. of Southwest Idaho. Retrieved 3 January 2010.
  5. ^ "Quadrant Roadway Intersection". Alternative Intersections/Interchanges: Informational Report (AIIR). Federal Highway Administration. April 2010. FHWA-HRT-09-060. Retrieved September 4, 2017.
  6. ^ Wilbur Smith Associates; Thompson Transportation; HDR; Hummer, Joseph E., Ph.D., P.E. (April 21, 2008). "Intersection Concept Layout Report" (PDF). High Volume Intersection Study (PDF). Community Planning Association of Southwest Idaho. Retrieved September 4, 2017.
  7. ^ Nelson, Catherine M., P.E.; Belleque, Kent; Crossler-Laird, Rich; Gutierrez, Rodger; Henson, Christopher; Lindland, Steve; Nguyen, Lily; Polly, Dave; Warrick, Dave (2012). "Chapter 2: Design Controls and Criteria" (PDF). ODOT Highway Design Manual (PDF). Oregon Department of Transportation. Retrieved September 4, 2017.
  8. ^ "Cary Parkway and High House Road Intersection Improvements". Town of Cary, North Carolina. Retrieved 3 January 2010.
  9. ^ "Archived copy" (PDF). Archived from the original (PDF) on April 12, 2015. Retrieved December 23, 2014.CS1 maint: archived copy as title (link)
  10. ^ Institut für Straßen- und Eisenbahnwesen am KIT: Entwurf und Bau von Straßen – Teil: Straßenentwurf. (PDF; 8,44 MB) Abgerufen am 7. September 2013.
  11. ^ Maze, T.H.; Hochstein, Joshua L.; Souleyrette, Reginald R.; Preston, Howard; Storm, Richard (2010). Appendix A, Detailed Green Book Review with Comments (PDF). National Cooperative Highway Research Program (NCHRP) Report 650: Median Intersection Design for Rural High-Speed Divided Highways (PDF). Transportation Research Board. doi:10.17226/22958. ISBN 978-0-309-43543-7. Project Number 15-30. Retrieved September 12, 2017.
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