Analysis of Traffic Flow Patterns and Movement Distributions at Selected Urban Roundabouts in Ilorin Metropolis, Nigeria

Abstract

Understanding traffic flow patterns and movement distributions at urban roundabouts is essential for effective traffic management and intersection planning. This study examined the traffic flow patterns and movement characteristics of four selected roundabouts: Oja-Oba, Pakata, Adeta and Mandate in Ilorin Metropolis, Nigeria. The study aimed to identify variations in traffic demand across the approaches and determine the distribution of vehicles according to their directions of movement. Data were collected through field surveys and video recordings of vehicular traffic during peak periods. Existing geometric characteristics, including entry width, radius, circumference and inscribed diameter, were also documented to describe the physical characteristics of the selected roundabouts. Traffic flow patterns were analysed across the approaches, while traffic movements were classified into left-turn, through traffic, right-turn and circulating movements. The results provided a comparative understanding of traffic distribution and directional movement at the four roundabouts, highlighting differences in traffic demand among approaches and the movement characteristics of each intersection. The study establishes a basis for understanding traffic distribution at urban roundabouts and provides relevant information for traffic management, intersection planning and future transportation studies in Ilorin Metropolis. The findings may also support evidence-based decisions concerning the management of traffic at roundabouts in other rapidly urbanising cities with similar traffic conditions.