EVALUATING THE TRAFFIC OPERATIONAL PERFORMANCE IN ADDIS ABABA: A CASE OF MEGENAGNA TO AYAT ROAD CORRIDOR

Abstract

Poor traffic performance is a major problem in many countries affecting urban traffic sustainable development at present. It has a significant effect on social, economic, and environmental. Due to economic development and urbanization, transport in Addis Ababa has faced traffic congestion problems. This paper presents a study on the evaluation of operational performance of traffic in Addis Ababa in the case of the Megenagna to Ayat road network by addressing the factors that cause traffic congestions. LOS, average delay, and degree of saturation were quantified for three roundabouts using SIDRA software to analyze the traffic conditions in the study area. And Levels of service for three road segments were quantified using HCM 2010. A multiple regression analysis using SPSS was applied to quantify the factors that cause congestion on the performance of the road network based on questionnaire and field data. From the analysis, average speed of Ayat to Yetebaberute, Yetebaberute to Sahilitmiheret, Sahilitmiheret to Megenagna road segments were 11.6km/hr, 6.3km/hr & 5.45km/hr respectively and it was 30.08%, 26.14% & 22.59% of the free flow speed respectively. The LOS of these three road segments was F, and the traveler perception score was greater than 5, indicating drivers perceived the worst service. And for the three roundabouts i.e., Sahilitmiheret, Yetebaberute, and Ayat roundabouts, the overall LOS was F, so the degree of saturation is greater than 1 with the overall average delay of 405.20sec, 211sec and 310.2sec, respectively. The results from SIDRA software indicated that the roundabouts are providing traffic service above their capacity during the peak hour. From the SPSS result of the mean-variance results are significant at 0.05(p-0.05), which means that the factors caused traffic congestion in the study area. The regression model developed with R2 of 0.985, which is greater than 0.7, which shows the model was reliable. Based on the result of the study, the roundabouts were over congested; their operational characteristics were unsatisfactory, serving beyond their capacity & at a poor level of service. And the roundabouts contribute significant effect for the performance of the segments. The performance of the road network was poor and cause significant delay for the user. The factors that contribute for the poor traffic performance in the study area were significant to cause congestion.