Study On The Disaggregating Model Of Traffic Mode Split And Application

At present, the traffic jams in the urban road becomes increasingly serious, and lots of troubles occurs with the dramatically increasing in private cars, The residents'daily trip survey data of Beijing city, in 2003, shows that the trip rate of private cars has already nearly caught up with that of buses. As well as we know, the loading capacity of a car is far less than that of a bus in the same area. If some effective measures are carried out, whice can make some passagers by cars transist to buses, the traffic condition in the urban's roads will be improved.In many countries, the congest toll policy are carried out and have already received some good effection, such as England and Singapore. Recently, Chinese gorvenment intends to carry out this policy in some areas with serious traffic jams, like Beijing city and Shanghai city. But, the key subject is how well the road traffic saturation can be improved. The application of the disaggregating model theory and method in the field of the traffic mode splitting has been considered as a groundbreaking thinking. Many reasearches show that the disaggregating theory has lots of advantages in etablishing the traffic mode choice model and evaluating the congest toll policy.The disaggregating model of traffic mode split is basic on the individual utility maximization theory. In the theory, the individual trip action is considered as the unit of analysis; the residents'daily trip survey data needn't to be delt with, but is indirectly used to etablish models. In the paper, the influent factors of the residents'choice for trip mode are analyzed from three areas: characters of trip, characters of tripper and transport services level. Then, some representative factors are selected as variables, and a multinomial logit model(MNL)for traffic mode split forecasting is etablished based on the theory of disaggregating modeling and the residents'daily tip survey data of Beijing city. The time value of the bus and that of the car are calculated according to the MNL model, and the generalized cost of these two modes are obtained and applied to establish a BNL Model, which is mainly used to accomplish evaluating the effection of the congestion toll.Six chapters are used to describe these techniques in details in the paper and now each chapter title and its main contents will be introduced respectively. 1.The purpose and significance of the research, the current research status in domestic and foreign countries, contents and methods being studied, and so on, are introduced in the first chapter.2.At first, the basic theory of traffic mode split is introduced in the second chapter. Then detailing analysis of the influent factors to the residents'choice for trip mode are given. Finally, some models for traffic mode split and their characters are introduced.3.In the third chapter, firstly, the basic theory of disaggregating modeling-the utility maximization theory is introduced. Consequently, the modeling thinking and the model's structure of the multinomial logit model are introduced and the calculating flowchart is given. Finally, the calculating method for the model'parameters is introduced.4.Through combining with the residents'trip survey data of Beijing city, in 2003, the choice group is determined, and the representative factors are selected as the Variables. Then a MNL model containing five traffic modes is established basicing on the Previous theory and method. Finally, Through caculatting the hit ratio, the model is proved to be an effective method. The model's calibration and verification are completed.5.In the empirical application part, the significance and the basic idea of the congest toll policy are introduced. Through calculating the generalized cost of the bus and the car according to the previous MNL model, a BNL is established which is used to analyze the changing of the road's saturation resulting from the different price of the congest toll, then the implementation effects of the congest toll policy. is evaluated.6.In the conclusion part, the main research contents and results and the contents need more study are summarized.The main results of this article are as follows:1.In this paper, the traffic mode choice model are established based on the disaggregating theory, and the evaluation to the implementation effects of the congest toll policy is accomplished. Then the disaggregating theory's significance in adjusting the traffic structure of the city and the application in the policy evaluation are introduced. 2.The influent factors of the residents'choice for trip mode are analyzed from three area: trip's character, tripper's character and transport services level. And some representative factors of the residents'choice for trip mode are given,then a MNL model for the traffic mode choice is etablished based on the data of Beijing.3.The unconstrained optimization function in Matlab Optimization Toolbox is used to estimate the model's parameters, which mainly uses the improvement method for Newton algorithm including the DFP algorithm and the BFGS algorithm.4.The MNL model has been used to calculate the value of time for the buse and the car, which is used to caculate the broad cost including trip time cost and actual money cost, then a BNL model for the traffic mode choices is established, which is used to analyze the changing of the road's saturation resulting from the price's changing of the congest toll.