Wahd Solomun2025-06-292020-06-28https://repository.mu.edu.et/handle/123456789/759Traffic congestion is a problem which occurs on road network characterized by slower speed, longer trip time due to excessive vehicles from different direction. Traffic congestion have a negative impact on society such as late reach to work place by increasing travel time, on health by creating stress, mentality and physical discomfort, increasing fuel consumption and air pollution. Mekelle is one of the fastest growing city in Ethiopia. Accordingly, traffic congestion is growing extremely in the city and results time wastage on travel and other direct and indirect effects on the society. This study is concentrated on two selected intersection the first one is four leg signalized intersection which is found around commercial bank of Ethiopia, main branch and the second one is four leg intersection which is found around Relief Society of Tigray in this intersection traffic light is not functional for about two years but after data collection performed the traffic signal was maintained and the intersection become signalized. Then again traffic volume data was conducted at signalized case. The main objective of this study is to estimate traffic congestion costs for selected intersection of Mekelle city and to suggest the possible counter measure for the problem. Primary and secondary data was collected to accomplish the study objectives. Primary data traffic volume, vehicle occupancy, signal timing, geometric data and daily labor cost was collected. The traffic volume count was made using video recording starting in the morning peak time 7:00AM-10:00AM, at noon time 11:00 AM-2:30 PM and the evening peak time 4:30 PM- 7:30 PM at 15 minutes interval was done for both intersections. The vehicles were counted by type passenger car, bus and small and medium truck vehicles. The average vehicle occupancy was collected based on traffic engineering vehicle occupancy data collection manual. After the data was collected data analysis was made. Delay at the intersection was analyzed using SYNCHRO software. Then using the collected data and delay annual peak hour cost of traffic congestion in both intersection was estimated. The cost of congestion consists travel time cost, fuel consumption cost and cost of co2 emission gas due to excess fuel usage. The result is found about (5,339,609.37ETB annual peak hour cost) at CBE four leg signalized intersection, (3,789,746.99ETB annual peak hour cost) at REST four leg unsignalized intersection, and (3,181,684.41ETB annual peak hour cost) at REST four leg signalized intersection. Annual peak hour travel time cost represents the opportunity costs of wasted time on congested intersection which shows the largest category at CBE intersection found about 4,311,552.5ETB nearly 81% of total cost of the intersection, at REST unsignalized is about 3,116,165ETB about 82% of cost of intersection and REST signalized have 2,618,690.9ETB about 82% of total intersection cost. Meanwhile annual peak hour cost of fuel is the second contributor to the overall cost of congestion with 1,009,870.3ETB at CBE, 661,988.9 ETB at REST unsignalized intersection and 552,987.4 ETB at REST signalized intersection which is about 18% of the total cost. On the other hand annual peak hour emissions costs is the least contributor to the overall cost of congestion and estimated about 18,186.57ETB at CBE intersection, about 11,611.09ETB at REST unsignalized intersection and 10,006.11 ETB at REST signalized intersection. The cost of congestion result shows the effect of congestion is highly concentrated on the travel time of public transport users’ means 78% of the travel time cost is for the public transport users.enThesis