Study Of Optimal Method For The Traffic Control In Urban Plane Intersection

The author attempts in this thesis to introduce in the first place the basic parameters and estimation indexes of the three types of traffic signal control and proceed to discuss respectively the basic ways of traffic signal control and its optimal method.The signal control of the isolated intersection has two basic parameters: the cycle length and the green split. The estimation indexes of the desired traffic effect are as follows: the traveling capability, the saturation, the delay, the frequency and the rate of the stops and start-ups and the fuel consumption. In addition to cycle length and green split, signal offset is also an important parameter of the artery and dimensional traffic signal control systems. The estimation indexes of the artery and dimensional traffic signal control systems often involve the overall optimal indexes in form of formal flexible strategy of the estimation indexes of several isolated intersections.The classic optimal means of isolated intersection is the TRRL and the ARRB. The thesis is devoted to the optimal model and impending algorithm of the signal time based on the gray control theory with the minimum delay and queuing traffic number as the target function and saturation as the restraining condition. The thesis also establishes an overall optimal index and its simulated annealing optimization algorithm that consists of performance indexes: the delay time, the stops and start-ups and the traveling capability. The realization of the traveling capacity control and elicitation system in the city is adaptive to the traffic situation in the changeable intersection at any given time. The synchronous and exact prediction of the traffic flow is the premise and key to the realization of these systems. The present thesis provides a method to predict the traffic flow in a short period by combining several prediction models and artificial intelligence.The thesis elaborates on the optimal method that is based on two typical estimation indexes: the maximum width of the two directional traffic flow and the minimum of the average delay time, i. e. the optimal signal timing method of the green wave tuning signal control and that of the minimum delay time summation of the average delay time.The thesis gives an analysis of the widely adopted signal control systems such as TRANSYT, SCATS and SCOOT and points out the disadvantages of the systems. The tend of the traffic control development in the cityis included.