Study on the Effect of Access on the Capacity of Signalized Intersection

In the calculation of urban signalized intersection capacity, the effects of road and traffic conditions, which includes on-street parking maneuver rate, local bus stopping rate but not the access. Traffic that drives in and out of the accesses have a negative impact on both the smoothness of the main road traffic and the capacity of the downstream intersection. An analysis of how the assess traffic affects the downstream signalized intersection shows that the merging or passing through of the access traffic leads to green time loss of the intersection. The green time loss can be expressed by the merging time of the access. A regression analysis reveals that the merging time of the passing through traffic have a correlation with the distribution of the main road, but not strong. Then, the capacity calculation model, which consider both the access traffic and the main road traffic arriving is formed. The model shows that accesses lead to the capacity loss of the signalized intersection. At last, the result of the model is demonstrated with a numerical example.