Paper Contents
Abstract
The meeting area of two or more roads is called an intersection. The traffic movements like through, turning and crossing traffic are present at the intersection which lead to different conflicts. These conflicts may be handled in different ways depending on the type of intersection and its design. The safety, efficiency, speed, capacity and economy of a road depend upon the intersection design. Roundabouts are special form of channelized circular intersection in which traffic moves in one direction around a central island before exits to various intersecting roads. It is a major form of at-grade junction featuring yield control on all entry lanes, one-way flow around a central island and appropriate geometric curvature to keep circulating speeds low. Depending on the size of circular traffic intersections it may be classified as Rotary, Roundabout and Mini-roundabout. Rotaries are suitable when there are more approaches and no separate lanes are available for right turn traffic thus making the intersection geometry complex. Rotaries were designed in the 1940's or earlier and work well at low volumes, but very poorly under heavy traffic conditions. Under low traffic conditions, a roundabout offers higher capacity as compared to a two-way stopped control or an all-way stop-controlled intersection. Roundabouts were developed in the 1960's and able to handle heavy traffic. Mini-roundabouts are best suited to arcas with low speeds and there is no feasibility to use roundabout with a raised central island. Mini-roundabouts are common in United Kingdom (U.K.), France, United State and Germany since their introduction in the carly 1970's.
Copyright
Copyright © 2025 Prabhat Kumar. This is an open access article distributed under the Creative Commons Attribution License.
