The Research On The Model Of The Intercity Traffic Mode Split And The Sensitivity Analysis Of Passenger Traffic

With the development of the urban agglomeration,the intercity traffic is becoming more and more important.As an important link of “four phases method” prediction,the mode split of the intercity traffic plays a decisive role in reasonable planning and efficient management of intercity traffic.Reasonable and effective model of traffic mode split can provide scientific decision basis for the future intercity traffic structure and the optimization of traffic control.This thesis studies the model of the intercity traffic mode split of the urban agglomeration from the perspective of passenger travel.The improvement way of the Nested Logit model is put forward to divide the intercity traffic mode.And an improved calculation method of the Nested Logit model is also designed.Combined with the coefficient which is calculated by the improved model,that of each factor of the utility function,according to the theory of passenger flow balance,using the variational inequality model,the model on the sensitivity analysis of passenger traffic is constructed.Taking Wuhan city circle as an example for the empirical analysis,this paper verifies the feasibility and effectiveness of the improved model,and analyzes the sensitivity relationship of various factors on the traffic utility function.Firstly,this thesis introduces the characteristics of urban agglomeration and intercity traffic.Through the analysis and comparison of various modes of intercity traffic,and combining with the intercity traffic travel characters,passenger travel qualities and service properties of intercity rail transit,this paper explores the prospect of intercity rail transit in intercity traffic.Secondly,according to the present situation of the mode split model at home and abroad,this paper gives a comprehensive overview about the related theory of the mode split model and traffic equilibrium assignment model.The aggregate model and the disaggregate model are analyzed in detail.Combining with the Wardrop equilibrium principle,this thesis introduces the user equilibrium model and the system optimal model.Then,based on the intercity traffic service characteristics of urban agglomeration,and combined with the utility theory,each factor and the measure method of the utility function are presented.And the utility function is built.Because of the existence of correlation between each way of the intercity traffic,this paper selects the Nested Logit model in the disaggregate model to analyze it.The Nested Logit model is used to calculate the probability of each mode of transport,which uses a fixed utility value.If the fixed utility value is bigger,the calculation results and the actual results can be lead to be different.In order to solve this problem,this paper improves the Nested Logit model,and uses a relatively fixed utility value instead of absolute fixed utility value.Using the maximum likelihood estimation method,the computational process of the improved model is set up.The t-test of the model and goodness-of-fit tests are given.Based on the traffic equilibrium allocation theory,combined the improved Nested Logit model with variational inequality model,the sensitivity analysis method of passenger traffic is put forward.Finally,taking the intercity line as the empirical analysis sample from Wuhan to Xianning in Wuhan city circle,comparing the calculation results of Nested Logit model with that of the improved Nested Logit model,this thesis comes to the conclusion that the calculation results of the improved model are more accurate than those of the original model,which verifies the feasibility and effectiveness of the improved model.Through the sensitivity analysis of the price factor and traffic,the position of the current ticket price of the intercity rail transit from Wuhan to Xianning and the influence of ticket price to the intercity passenger traffic are analyzed,which can provide theoretical reference for predicting future intercity traffic mode split.