ASSESSMENT OF TRAFFIC CONGESTION AND ITS IMPACT OVER SELECTED ROAD CORRIDOR IN ADDIS ABABA CITY

Abstract

Traffic congestion problem is becoming a common problem in most developing countries of world. This study was conducted with an objective making assessment of traffic congestion and its impact over the selected road corridor in Addis Ababa City. Through reconnaissance survey the corridor from ‘Awutobis Tera’ Bus station to ‘Lamberet Menahereya’ in Addis Ababa city was identified and for analysis purpose the corridor was divided into three sections. The study was conducted starting from June up to October, 2019. Both quantitative and qualitative approach were used. 384 samples were used to conduct questionnaire survey for traffic congestion cause analysis. Out of this 32.5% of the required sample were drawn from section A, 27% from section B and the rest 40.5% was from section C. For making analysis on the performance level of road corridors and economic cost of traffic congestion, traffic volume, travel time delay, average travel speed and vehicle occupancy data were collected manually for a period of 12 hours a day at 15 minutes intervals on respective road corridors and for intersections the data were collected for two hours interval during rush periods. In addition to traffic condition data, the geometric data were also measured as part of the study. The analysis on causal factors for traffic congestion was conducted by SPSS software and analysis on level and economic cost of traffic congestion of the selected road corridor was conducted by utilizing both SIDRA and Microsoft excel. Based on the result of analysis multi variable linear regression model, the imbalance between vehicle volume and road capacity, number of pedestrians that cross and move along the side of the road, inflexible work schedule, inadequate mass transit service along the corridor and illegal on street vehicle parking were identified as the main causes of traffic congestion over the road corridor. As the result from SIDRA and Microsoft excel showed that the intersections along the corridor and the road corridor in section C were operating beyond the standard set by HCM 2010 which recommends LOS ‘C’ or ‘D’. As per the economic analysis result of the study showed about 2667.8 person-hours/year and ETB104048.75 /year per individual traveler are being wasted due to traffic congestion over the study road corridor. Building vehicle parking apartment, elevated pedestrian crossway and improving performance of intersections were some of the engineering measures recommended to overcome the traffic congestion problem of the corridor.