A quadrant roadway intersection adds an additional "quadrant roadway" between two legs of an intersection. This roadway adds two

three-way intersection A three-way junction (or three-way intersection) is a type of road intersection with three arms. A Y junction (or Y intersection) generally has three arms of equal size coming at an acute or obtuse angle to each other; while a T junction (or T ...

s in addition to the original four-way intersection moving all left turns (in

right-hand traffic Left-hand traffic (LHT) and right-hand traffic (RHT) are the practices, in bidirectional traffic, of keeping to the left side or to the right side of the road, respectively. They are fundamental to traffic flow, and are sometimes referred to ...

countries) or right turns (in

left-hand traffic Left-hand traffic (LHT) and right-hand traffic (RHT) are the practices, in bidirectional traffic, of keeping to the left side or to the right side of the road, respectively. They are fundamental to traffic flow, and are sometimes referred to ...

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 places where accidents could occur from vehicles potentially crossing paths as well as a low development cost compared to

roundabout A roundabout is a type of circular intersection or junction in which road traffic is permitted to flow in one direction around a central island, and priority is typically given to traffic already in the junction.''The New Shorter Oxford En ...

s or the more complex

single-point urban interchange A single-point urban interchange (SPUI, or ), also called a single-point interchange (SPI) or single-point diamond interchange (SPDI), is a type of highway interchange. The design was created in order to help move large volumes of traffic thro ...

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 rebut low cost claims pointing to right-of-way and construction costs of the quadrant road. A related structure known as a

jughandle A jughandle is a type of ramp or slip road that changes the way traffic turns left at an at-grade intersection (in a country where traffic drives on the right). Instead of a standard left turn being made from the left lane, left-turning traffic ...

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.

Quadrant interchanges

An interchange variant of the quadrant roadway intersection links

grade-separated In civil engineering (more specifically highway engineering), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other tran ...

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 or as a single-loop intersection. This type of junction is common in Germany, where it is called a "partial at-grade intersection" (). 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).

References

{{Road junction types Road junction types