CAPACITY EVALUATION AND LEVEL OF SERVICE AT SIGNALIZED INTERSECTION IN HAWASSA CITY

Abstract

Signalized Intersections are usually considered as the critical points within the urban road network and the evaluation of their performance provides valuable understanding and useful indication about the performance of the city road network system. The capacity of signalized intersection is more significant because such intersections often control the ability of the city streets to accommodate traffic. The main objective of this study is to evaluate the capacity and level of service at the signalized intersections in Hawassa city, based on traffic and geometric characteristics. To achieve this objective, four signalized intersections in the city from major road corridors were selected for this study. This intersection is located in the western central part of Hawassa city. They have heavy traffic volume, with higher delay and heavy congestion traffic more than any other similar intersections in Hawassa. The required field data was collected in the selected signalized intersections which includes the approach traffic volume, saturation flow rate and approach road widths in each phase by using Video recording and manual transcription. The data was collected at every 15 minute consecutive intervals covering both peak and non-peak hour. From the data collected, the degree of saturation (V/C ratio) was evaluated and the level of service of the intersection in each phase was arrived. Peak hour volumes were estimated at morning and evening. Volume/Capacity (V/C) ratio, Vehicle delay and level of service (LOS) were analyzed by using SIDRA software. Traffic delay was also estimated as a part of the study by conducting fixed time delay study. The results obtained in the present work may bring some guidelines to modify the signalized intersections