High urbanization rate and Economic development has caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at congestion places are a few to mention. Road traffic congestions are caused by inadequate infrastructures, long signal cycle time and poor traffic management. The research study was focused on the methods of improving traffic congestions, delay and level of service at selected signalized road intersection in Addis Ababa city. The data needed were; road geometry data, signal data, traffic vehicles flow data including the pedestrian data were collected on peak hours for four consecutive working days. Data analysis and processing have been performed using SIDRA (Signalized and unsignalized Intersection Design and Research Aid) intersection software in order to know the traffic flow condition at the intersection. The outcomes of the research work minimize average time delay by adopting different improving strategies that range from low-cost measures such as improvements to signal timing and phase numbers, to high-cost measures such as intersection reconstruction.