Study On Optimization Method Of City Traffic Micro-circulation Network Under Multiple Constraints

At present, our country is in a period of rapid development of social economy,urbanization and motorization process will continue to accelerate, dependent on carsexacerbated the city traffic congestion, traffic safety, environment pollution, energyshortages and a series of problems, which seriously affect the sustainabledevelopment of the city traffic, economy and society in China and the improvement ofpeople’s living standards. In the management of traffic congestion, the governmentand relevant departments are pay attention to the construction of high grade roads inthe city, but ignore the low grade roads, as a result, causing the city road networkgrade proportion uncoordinated, and appearing more congestion problems. Therefore,increasing the proportion of branch and lower grade roads and the coordination of thewhole city road network scale is the main way to solve city road congestion service.These microcirculation road system consist of branch and lower grade roads canalleviate the city traffic pressure, share the road network traffic demand, provide safeand convenient transportation service for area residents.Aiming at the level of city road network does not match, this paper puts forwardthe micro circulation loop network optimization algorithm to optimize trafficmicro-circulation roads, so as to increase the proportion of branch and lower graderoads, release the congestion of main roads. The paper first analyzes the presentsituation of research on theory of traffic micro-circulation, road optimization method,road engineering practice at home and abroad, clears the traffic micro-circulation inthe significance of the city road traffic, and then analyzes the main problems anddisadvantages of optimization method of traffic micro-circulation, and on the basis ofexisting research, constructs the multi constraints of traffic micro-circulation networkoptimization model, the optimization process mainly includes: research on theregional trunk road congestion, traffic micro-circulation detour route search andbuilding of traffic micro-circulation optimization model. Building a multipleobjective function and bilevel programming based on the traffic micro-circulation,solving the problem by the genetic algorithm, at the end, we can get the optimal scheme.The optimization model of traffic micro-circulation considers various factorsaffecting the road network in paper, establishes the evaluation index system of trafficmicro-circulation network, and expounds the principles of establishing the evaluationindex, then builds a city transportation network optimization traffic micro-circulationevaluation system from three aspects, which is the technical performance, economiccost, social and environmental impact. The paper analyzes the meaning of each index,the calculation method and significance in detail, quantify the evaluation index as faras possible, and provides the standard for program evaluation;At the end, The optimization model of traffic micro-circulation studiedemphatically and examples of key verification. This paper selects the typical trafficmicro-circulation network as the study area, using the model under the multipleconstraints to rebuild the regional road network, and obtain the possible new roads,through the optimization model to solve the optimal solution, then evaluate andanalyze the optimal scheme. The example verifies the feasibility of the model in thepaper, and it has important reference value to the optimization of trafficmicro-circulation.