Traffic Network Performance Research Based On The Maximum And Minimum Speed Limit

With the rapid development of economic construction in China,the motor vehicle industry grows rapidly.By contrast,the growth rate of annual urban road construction in our country is less than the annual growth rate of car ownership.As a result,the contradiction between fast growing traffic demand and limited traffic supply leads to serious traffic congestion problem in many cities of China.Therefore,the traffic network management has drawn more and more attention from both government and academic field.On the one hand,based on the minimum speed limit in the actual traffic network,this paper creatively introduces the minimum speed limit to the user equilibrium research in the traffic network.The result shows that although the user equilibrium status changes after the introduction of maximum and minimum speed limit in the road at the same time,user equilibrium solution still remains and has uniqueness in the range of feasible solution.At the same time,this paper designed a simple example to prove the existence of the user equilibrium solution for illustration.On the other hand,based on the obvious differentiation between fluent state and crowded road of the resistance function in the traffic network,the paper modifies the original BPR road resistance function model and divides it into three parts.On this basis,by using a variety of mathematical reasoning method,the paper proves that we still could find user equilibrium solution in the traffic network with the maximum and minimum speed limit in the road within a certain range.Finally,the paper uses an example of symmetric traffic network to analyze the network performance including the total traffic time and total traffic emission in the system.It is concluded that when we set the minimum speed limits for different traffic road in a reasonable range,it not only can reduce the system total travel time,also can bring the system total emission reduction,which is quite instructive for the government traffic management.Based on the theoretical research of the maximum and minimum speed limit in the road and revised BPR road resistance function,the paper could provide the government with a new perspective and direction for actual transportation network design,planning,operation and management.