Considering The Research On The Distribution Of Cross-border Freight Network Flow Under The Constraints Of Highway Ports

In the trend of continuous tension and growing demand for cross-border cargo transportation capacity,the western road ports as nodes to undertake domestic and international freight transport have been experiencing varying degrees of congestion and delays.In recent years,highway port constraints have led to frequent transport delays,and the level of infrastructure has gradually become a "bottleneck" limiting the development of ports and an important factor threatening cross-border transport time.Smooth and efficient cross-border transportation is the basis and guarantee of crossborder trade,and the port constraint not only affects the sustainable development of cross-border transportation,but also brings great pressure to other transportation industries.Most of the measures to improve the efficiency of network transportation by improving transportation infrastructure,such as increasing roads and manpower,are time-consuming and costly,and have little effect.Therefore,how to achieve efficient docking of cross-border logistics cooperation by improving the utilization rate of existing infrastructure is the top priority for the stable and sustainable development of cross-border trade in the future.The network is the carrier of the flow of traffic,and exploring the structural characteristics of cross-border freight network is of great significance to the flow distribution process.Therefore,this paper combines complex network theory to systematically evaluate the importance of highway port nodes in the network,laying a theoretical foundation for the subsequent impact of highway port nodes with constraints on network transportation,and revealing the evolution law of cross-border freight network structure in recent years,and digging the impact of impedance effect of highway port on cargo flow in the dynamic distribution process of network flow.Specifically,the research work of this paper mainly includes the following aspects.1.This paper summarizes the research direction of cross-border transportation,the main direction is the intrinsic mechanism and influence factors of cross-border channels,etc.,both in theory and practical application have been developed more mature,but very few scholars to the perspective of the port hubs to build cross-border freight network on cross-border transportation research,and for the node impedance role on the impact of network flow is a gap,so this paper has a certain Research value.2.Using complex network theory to study the spatial and temporal evolution of cross-border freight network,we analyze the problems in the analysis of the strength,advantages and dynamic transportation process based on the linkage between road ports and cities of origin and destination.On this basis,the topological structure of crossborder freight network in the study area is constructed based on the linkage strength between nodes in the Lan-Me cooperation region,and the statistical feature vectors of nodes and their structural evolution are analyzed by network visualization in 2010,2014 and 2017.The results show that the linkage strength in the study area shows a dense northeast-southwest trend using Arc GIS visualization.The network edges are assigned with the connection strength between nodes,and the dynamic evolution of the crossborder freight network is analyzed in depth based on the complex network theory,and the basic statistical feature indicators in the study area are analyzed with the help of Python software.The network is overloaded and has a large impact on the overall transport efficiency when delays occur.3.The impedance of road ports to cargo flow is a key factor affecting the throughput of the whole cross-border freight network and the formation of port delays.The degree of delay at road ports directly affects the transport efficiency of cross-border freight network,so the delay at road port nodes is considered into the construction of cross-border freight network,and the threshold value of port service capacity is defined with reference to the U.S.road congestion evaluation index.A cross-border network dynamic flow allocation algorithm considering the port constraints is synthesized and proposed,which fully considers the impact of the degree of delay of road port nodes on the total network cost and the cross-border cargo flow path allocation.The results show that when the service efficiency of road ports is low,which has a certain impedance effect on the cargo flow,most of the cargo flow will choose to continue to be cleared by the original port,but due to the increase of delay cost,it also forces a small part of the traffic to be transferred to alternative ports for clearance,and the selected path reset traffic are captured by the neighboring ports.