Research On The Influence Of Cycle Time On Saturation At Signalized Intersection

With the development of urban mechanization course, the numbers of cars increase, however the lane areas are limited, and the congestion problem is more and more serious, and intersections of some cities are so congested that people can't put up with. Intersection is the bottleneck of urban traffic, and also the conflict point of the congestion. In order to resolve the congestion problem of signalized intersection and improve the operation efficiency of intersections, it is found that many signalized intersections increase the length of cycle time, so we can find cycle time as long as 160s, 180s and even longer than 200s. However, in this case, it is necessary to study if the saturation is stable, if the capacity is increased and if the congestion problem is resolved.The main research subjects and innovative contents of thesis are as follows:Firstly, on the basis of the analysis and overview of the main problem of signalized intersection, including the basic influence factors and the requirements of design of signal timing. And Discussed the study on the cycle time and the conclusions of the studies on the long cycle time.Secondly, on the basis of the analysis and overview of theories of saturation and capacity, summarize and compare these methods of their surveys.Thirdly, three processes (the theory analysis, the traffic survey and the microscopic simulation), research on saturation influenced by the length of green time when it has an expanded lane or not. The disadvantage of the long cycle time is summarized, and the optimal length of green time is provided.Lastly, based on the conclusion of the influence of green time on saturation, obtain the optimal green time when the saturation is largest.The thesis study on the design of green time and cycle time at a new aspect, and obtain the relationship between saturation and green time.