Study On Traffic Assignment Of City Center Area Based On Improved Logit Route Choice Method

In recent years,with the development of social economy,the proportion of urban motorized travel has been improved,and urban traffic problems,especially in the city center area,have become increasingly prominent.To solve the traffic problem,it is necessary to pay attention from the traffic planning.Traffic assignment is an important content in the traffic planning.In the process of traffic assignment,the route choice of the traveler is the focus of the traffic assignment problem.In the study of choice of travel route problems,the most commonly used is the Logit route choice method.However,in the traffic assignment of the macro-level network,Logit route choice method has some problems like routes exhaust and complicated calculation process.The network of city center area belongs to the mesoscale level network,the traffic characteristic is more consistent,and Logit route choice method has great superiority to the traffic assignment problem in city center area.In this context,this paper improves the traditional Logit route choice method,and puts forward the road resistance function for the division of road grades,and puts forward the reasonable solution to traffic assignment problem in city center area.This paper first defines the concept of the city center area,introduces the traffic travel characteristics of city center area,studies the choice of travel route in city center area,and summarizes the influence of road grades division on travel route choice.Secondly,the influencing factors of the road resistance function are analyzed,and the function form and applicability of the commonly used road resistance function are expounded.According to the different road grades,the road resistance function of city center area considering the road grade is established.Then,the method of calculating the flow distribution rate in the traditional Logit route choice method is improved by using the road resistance function of city center area divided by the road grades,and the traffic assignment method of the urban central area is constructed by combining the successive equilibrium algorithms in the multi-path allocation method,and design an example.Finally,through the traffic demand forecast of F area,the traffic assignment method is used as an example to analyze the results.In this paper,the improved Logit route choice method is used to study the traffic assignment problem in city center area,and the road resistance function considering the road grades is proposed.The calculation method of the path flow distribution rate is improved and the final distribution result is reasonable.Providing the transportation department management a certain scientific basis.