Adaptability Analysis of Classical Signal Control Theory Applied in Crowded Traffic Environment

To solve the problem that the capacity of signal intersection decreased when the classical signal control theory was applied in crowded traffic environment, such as Webster, HCM, and so on. First, the leaving demand of traffic participants at signal intersection was analyzed both in non-crowded and crowded traffic environment. Second, based on the goal to reflect the fair of traffic participants' rights, the total rights of traffic participants in different traffic environment was deduced using the method of delay triangle at signal intersection, and the relational models between rights of traffic participants and split were developed. The results indicated that classical signal control theory such as Webster considered the fairness of traffic participants' rights and obtained good effect in non-crowded traffic environment. However, in crowded traffic environment, the signal control program drafted only from traffic volumes met some limitation to solve or relieve the traffic congestion. Therefore, it is necessary to consider other factors caused traffic congestion to improve the existing signal control theory.