STUDY OF SOME INTERSECTIONS AND SUGGESTED IMPROVEMENTS-A CASE STUDY OF PATNA CITY

Abstract

As the population of urban areas and the vehicle ownership are increasing very fast, whereas the road network has remained unchanged over the decades. The traffic flow has also become complex in nature. To deal with the traffic suitably, overhauling of the entire road pattern is essential which will take quite sole time and require large quantity of funds. Yet, one can not wait till this is done. As such, the measures at the warranting locations need to be taken up immediately to allow smooth flow of traffic. Such locations arc the major intersections and overcrowTr ded narrow roads. The present study is undertaken for six major intersections in Patna city, which are having acute problem of handling traffic. An at grade intersection is the most common type of junct4qn on roads in India. These at-grade intersections may be signalite_cf or non-signalized. A very little work has been done on non -signalized intersection in India which are having complex mixed traffic flow. On all the six intersection, extensive data for classified directional traffic volume count, approach speed and other geometric features were collected and analysis has been done. On basis of the analysis the improvements in all the six intersections are recommended. In order to improve the efficiency of operation of the intersection under study, maximum consideration has been given to the following aspects :- (i) Sight distance. (ii) Turning radius. (iii) Traffic characteristics. Sight lines were scientifically checked and attempts have been made to provide at lebtt the minimum recommended sight distance at the intersections. Turning radii have been decided on the basis of prevailing speed of the traffic streams and the availability of the road 1 ids. Traffic characteristics have dictated the choice of the type of control, the number of lanes etc,. and these are suggested.