Gebresenbet, Girma (Professor)Taddesse, Wondwossen2018-07-232023-11-112018-07-232023-11-112011-09http://etd.aau.edu.et/handle/12345678/9747Traffic Congestion is an ever growing chronic problem in the transportation system soon after the invention and mass production of automobiles. All major cities both in developed and developing countries are facing the problem due to increasing travel demand which follows economic and population growth. Traffic congestion directly affects commuters with an increased travel time, excessive delay in a queue, increased fuel cost, delay for important appointment and job, loss in productive hours; and it indirectly affects the living standard and the environment as well. Hence, traffic congestion cause upon road users and cities to incur a significant amount of money for both economic and social costs. Quantifying the level of the traffic congestion and understanding how much effect and cost are being incurred due to traffic congestion; hence, will be important for making improvement decisions and evaluate implemented mitigation measures. Following the economic and population growth in Addis Ababa, traffic congestion problem has emerged and the problem is even growing faster. In this study, the level of the traffic congestion in Addis Ababa city was quantified using travel time approach. The city’s one of the most congested East-West corridor was considered and travel time, traffic volume, and vehicle occupancy data were collected at four midblock and four intersections. Accordingly, the travel rate, the delay rate, total travel delay (Veh-Min and Per-min), buffer index and planning time index were calculated. And also, the average hourly travel rate is correlated with the average hourly traffic accident data and congestion spots and accident black spots were plotted on the GIS map to see the relationship between the traffic accident and traffic congestion. Accordingly, the result showed that on average about 18,000 Veh-min or 38 Veh-day and about 169,000 Per-min or 352-person-day are wasted at each major intersection entry and the city incurs annually about 5-8 Million Birr per intersection only for vehicle and fuel cost. The result also showed that the city’s traffic accident rate correlated with travel rate better than traffic volume and the congestion spots identified from questionnaire data conside with the black spots identified by the national road safety agency.enRoad and Transport EngineeringThesis