Research On The Optimization Of Freight Transportation In Beijing Under Urban Traffic Limits

ABSTRACT:City logistics is inseparable from city development and pepole’s lives, the main logistics feature of Beijing as a large city is input-based and city-distributed. Freight traffic measures are strictly implemented within the urban limited areas in order to transfer the traffic flow produced by urban freight to off-peak hours, which largely increases the cost of urban logistics, reduces the customers’ satisfaction degree of distribution and inhibits urban logistics development. Thus the optimization of urban freight transportation under the background of city traffic limits has become an urgent problem in city logistics. The urban freight optimization strategies are proposed in this article based on the characteristics of city freight-traffic situations in Beijing.Firstly, the situations of freight-traffic in Beijing are analyzed from the aspects of freight demand, freight infrastructures, transportation tools and some associated freight policies. With the field research and information finding the layout characteristics and the existence problems of main logistic points among the traffic limit affected areas are obtained and analyzed. This paper proposes a two-tiered transferred-reloading distribution model according to the characteristics of urban freight transportation, and the proposed model provides a theoretical basis for the optimization of urban freight transportation under traffic limits.Then from the perspective of macroscopic and microscopic the traffic features of some main area sited inner ring in Beijing are analyzed. By use of FCM clustering and mean-variance statistical method this paper launches a spatial-temporral exploring analysis on the traffic limits affected regions. In the meanwhile the regional traffic evolution rules are investigated with the combination of metric characteristics and normal test method, which provides transportation feasibility analysis for the optimized urban transferred-reloading transportation model.Considering the current situation and existence problems of freight traffic in Beijing, a two-tiered freight optimization model based on the coordinated and transferred-reloading ideology is proposed and descripted with mathematical linguistics. With the consideration of vehicle travel cost, environmental pollution cost and customer distribution cost the optimized city freight model is conducted. An optimized algorithm based on genetic algorithm is designed to improve the searching efficiency and credibility of the calculated results.Finally, the validation to the proposed city freight optimized model under urban traffic limits is done with the example of certain-sized logistics points and cargo demand points within the fifith ring in Beijing. By using Matlab programming tool the designed algorithm is solved, and from the perspective of freight undertaking proportion, distribution timeless and logistics cost the calculated results are analyzed. The evaluated analysis shows that the proposed urban freight optimized model in this paper can reduce total logisyics cost as well as improve customer time satisfaction. The optimized model is fully accord with the requirement of raising the level of logistics services, and it can solve the problems existed in city freight under congestion to a certain extent and promote the urban logistics development.