The Study Of Organization Optimization Method And Assessment For Urban Traffic Micro-circulation

With the spreading of the block system and the residential district and office building being opened, the urban traffic micro-circulation system will play an increasingly important role in alleviation traffic congestion aspect. At present, most of the urban traffic micro-circulation organization schemes mainly based on experience leads to the inefficiencies of the micro-circulation; the lack of complete evaluation index system for evaluation of micro-circulation system and the actual use of trunk road evaluation index results in unreasonable evaluation of the actual operation effect of the micro-circulation system. Thus, the paper studies the organization optimization model and system evaluation of the urban traffic micro-circulation, whose aim is to provide the theory and the method instruction for the implementation of traffic micro-circulation.Regional, long-term, motor vehicle traffic micro-circulation is taken as the research object in this paper, and based on it the further research is carried out. As for the traffic organization optimization model, the minimization function of the vehicle travel time is established, through constructing the traffic impedance function of no signal control and two phase signal control intersection, and special phase of left turn control intersection, which combined with the road traffic impedance function. Afterward, terming to minimize above function, the minimum function of average saturation and minimum function of the environmental impact as the optimization objective, the paper optimizes road network traffic organization form the two aspects of the one-way traffic and the flow of the intersection, and creates a bi level programming model, whose upper level takes traffic organization scheme of microcirculation system as the decision variable and lower level takes traffic flow of all sections and intersections as the decision variable. According to the structure and characteristics of the model, the genetic algorithm is designed to solve the model. Meanwhile, taking into account the influence of the organ courtyard in the example analysis of micro-circulation network, it presents traffic situation analysis of combination scene, and the four kinds of scene are: before and after the removal of the wall and before and after the traffic organization optimization. It is clear that traffic operation after the traffic organization optimization is the best with the removal of the wall. While verifying the validity of the proposed model, it indicates that the opened compound can alleviate urban traffic congestion to a large extent. With special reference to evaluation of micro-circulation system, the evaluation indexs are selected through the grey correlation analysis method and principal component weighting method, also the evaluation index system of traffic micro-circulation system is established. In view of the difficulties of membership function in fuzzy comprehensive evaluation, the paper uses the gray correlation analysis method to determine the membership degree of each index in the fuzzy comprehensive evaluation, and proposes the fuzzy comprehensive evaluation model of traffic micro-circulation.Finally, taking the area of surrounding by Lingyun Road, miners Road, Guangming Road and Jianshe Road in Pingdingshan as an example of case study, the design of traffic organization optimization scheme is proposed and the micro-circulation system is evaluated to verify. It is shown that the implementation effect of the micro-circulation system after traffic organization optimization is in the middle level, at the same time, the efficiency of traffic micro-circulation organization optimization model and algorithms proposed in this paper is verifiedIt is worth mentioning that by constructing the model of the traffic organization optimization and the evaluation index system of traffic micro circulation system, the design of the organization optimization scheme and the determination of the evaluation index for traffic micro-circulation are more scientific and reasonable; in addition, from the aforementioned analysis of the traffic situation before and after opening Organ compound, it supports our country’s policy correlated with the spreading of the block system、the gradually opening of the residential district and office building.