Study On Signal Control Model And Algorithm At Isolated Intersection Based On Dynamic Time-of-Day

The signal control for intersections is the basic unit of urban road traffic control system. It is the key factor for determining lanes'capacity, travel time, traffic delays, traffic safety and sustainable development of urban traffic. At present, there are still many intersections in China using signal control facilities independently. It is an ur-gent traffic control problem to improve the existing control programs that how to further improve the efficiency of urban traffic control systems on the basis of the ex-isting facilities. In the principle of low-input and high-performance, we have intro-duced the traffic control situation in China, and designed the signal control system at isolated intersection based on the dynamic time of day breakpoints.According to the technological process for multi-interval traffic signal system, we have studied the development of time of day breaks, and the signal timing plan successively. A multi-objective optimal signal timing model based on robust ideology has established. Additionally, we verified the effectiveness of the timing program by examples.Firstly, on the basis of analyzing the dynamic traffic data collection and study-ing pretreatment methods, we has laid emphasis on Fisher clustering algorithm and done some improvements, and then applied the innovative Fisher algorithm in opti-mization of time of day breakpoints in traffic signal control, which is verified feasi-bility and validity through an example.Secondly, based on the summary of existing delay formulations of vehicles in intersection, we have introduced robust ideology which takes into account the uncer-tainty of traffic flow, and analyzed the relationship between intersection's vehicle-delay and signal cycle, capacity of intersection and signal cycle. Then the mul-ti-objective optimal signal timing model have been established.Thirdly, we have focused on studying NSGA-â…¡algorithm which is often used in solving multi-objective models. There are some improvements proposed for the al-gorithm. The innovative NSGA-â…¡algorithm has been successfully applied on the signal timing model proposed. Examples show the algorithm is efficient. It has been demonstrated that multi-objective model has better control effect than the existing program, the single objective timing model and the classical Webster timing model by simulation results.Finally, the research and development, as well as the following improvement of this paper have been summarized.