Comparison of Saturation Flow Rate at Signalized Intersections in Yokohama and Dhaka

The evaluation of capacity at signalized intersections is an important component in the proper planning, design, operation, and management of urban road street network. A procedure for determining the saturation flow rates at signalized intersections is presented in this paper; the procedure differs substantially from the procedure as discussed in the Highway Capacity Manual (HCM). ANalysis of VAriance (ANOVA) was performed to determine the saturation flow region of the queue for different queue regions. Saturation headway was estimated by averaging the headways of all the vehicles in the saturation flow region. A comparative study was then made between these two methods for different signalized intersection approaches in two metropolises, namely Yokohama, Japan and Dhaka, the capital of Bangladesh. The findings of this study suggests that the procedure as discussed in the HCM overestimate saturation flow rates for some approaches and underestimate for the other approaches. From the observed data it was evidenced that the headway values of passenger cars in the Dhaka metropolis are lower than that of in Yokohama.