SIMULATION ANALYSIS OF TRAFFIC CONGESTION AT UNSIGNALIZED CIRCULAR ROUNDABOUT USING MICROSCOPIC TRAFFIC FLOW MODEL

Abstract

The Effective management of roundabout is very important as a part of the current traffic infrastructures in developing countries. A comprehensive understanding of its dynamics especially at unsignalized roundabouts is imperative. In this paper, we study and present a Microscopic Simulation of traffic in an unsignalised roundabout using a Microscopic Car Following model based on the Intelligent Driver Model (IDM). At an unsignalized roundabout, traffic flow relies heavily on the principles of yielding and right-of-way. Vehicles entering the roundabout must yield to circulating traffic already inside. This dynamic often leads to a smoother flow compared to traditional intersections with traffic lights. However, during peak hours or when drivers fail to yield properly, congestion can occur, causing delays. Proper understanding and adherence to roundabout rules are essential for maintaining efficient traffic flow and preventing accidents. Hence, this paper delves into the mathematical modeling of traffic dynamics specifically tailored for unsignalized circular roundabouts. we meticulously examine mathematical models governing traffic flow, treating it as a continuous phenomenon, while delving into their inherent limitations. The impacts of the additional straight and turning movements in the Intelligent Driver Model (IDM) on traffic dynamics inside the circular roundabout are numerically analyzed using MATLAB, employing a fourth-order Runge-Kutta method after Fast Fourier Transform(FFT). Four Vehicles are put in a simulation environment over a specified period of time over which they are considered for analysis and the simulated results culminate in the determination of the range of velocities for three different types of movement considered in the analysis and different types of manoeuvers serving as a gauge for roundabout capacity and management. This study furnishes invaluable insights for scientist and road engineers involved in roundabout design in developing countries.