Quadrant roadway intersection
Encyclopedia
A quadrant roadway intersection adds an additional "quadrant roadway" between two legs of the 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.

Proponents also point to a reduction in points where accidents could occur from vehicles potentially crossing paths as well as a low development cost over roundabout
Roundabout
A roundabout is the name for a road junction in which traffic moves in one direction around a central island. The word dates from the early 20th century. Roundabouts are common in many countries around the world...

 or the more complex single-point urban interchange
Single-point urban interchange
A single-point urban interchange , also called a single-point interchange or single-point diamond interchange , is a type of highway interchange...

 designs. 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 refute low cost claims pointing to right-of-way and construction costs of the quadrant road.

Variants

Single quadrant intersections (pictured above) feature a single quadrant road. Double quadrant intersections add an additional quadrant road placed opposite of the other quadrant road. Another variant links grade-separated roads via the quadrant road, typically to bring together a faster road with denser traffic with an overpass
Overpass
An overpass is a bridge, road, railway or similar structure that crosses over another road or railway...

 (or flyover
Overpass
An overpass is a bridge, road, railway or similar structure that crosses over another road or railway...

) over a less traveled, slower road. This design is also referred to as a single-loop intersection.

Canada

The single-loop variant is used frequently in the Thornhill
Thornhill, Ontario
Thornhill is a community in the Greater Toronto Area of Southern Ontario, Canada, located on the northern border of the city of Toronto. Once a municipal village, Thornhill is now a community and postal designation geographically split into two municipalities along Yonge Street, the city of...

 area, in the Greater Toronto Area
Greater Toronto Area
The Greater Toronto Area is the largest metropolitan area in Canada, with a 2006 census population of 5.5 million. The Greater Toronto Area is usually defined as the central city of Toronto, along with four regional municipalities surrounding it: Durham, Halton, Peel, and York...

 in Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Canada, examples include:

United States


Germany

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK