The Study On Multi-mode Variable Demand Combinatorial Stochastic Equilibrium Model To Urban Transportation

The urban transportation can directly influence the city's social development and resident's everyday living ,it is an indispensable basic elements to the normal performing of the city facility. But as primitive planning and managing .there are serious problems now on the transportation part. A new .practical systematic method must be developed to alleviate these negative effects. For this purpose, it will require the examination of several issues, first, the behavior of individual travelers must be described as being the basic elemental determinants of travel demands. Behavior means the travel -related choices individual makes under given circumstances .for example, choosing whether to travel in a given time period, and choosing a destination, mode ,and route of travel. Second, individual choices must be aggregated to the level of travel flows, or volumes, this require the examination and formulation of how individual behavior interest, specifically congestion, a major fixture of urban travel, causes each individual traveler's options to be affected by the travel choices of all others. As a result .aggregate travel patterns reflect an equilibrium between all these individual choices, which must be identified. -eIn this dissertation ,an overall framework composed these four aspects a^ derived and an combinatorial model involving travel choice .destination choice ,mode choice .route choice ate successively formulated .these models are based on the theory on the individual's travel behavior that each level of the travel decision a\e somewhat random and the characteristic of the mixed traffic of Chinese urban transportation ,it presents an effective tools for the solution to the already-serious transportation problems.As we know , whether the transportation network is in equivalent or not ,is up to whether the equivalent conditions can be contented .when the random variable$Df the four aspects of choices are independent and of Gumbel distribution with different parameters , this dissertation proved that these conditions can be rewritten in mathematical expressions. This mathematical expressions are formed the first combinatorial model .the author then use a simple example to illustrate the validity in practice .When the deterrence function are symmetric , the author developed a minimum extreme value model which a\e* in equivalent to the first combinatorial model and its solutions are unique .using this method to solve the same example .the results are the same as expected .When the random variables of the four aspects of the choices are of general distribution .the author derived the equivalent conditions of the transportation networks which formed the second combinatorial model and develops another extreme value model with theunique solution which is in equivalent to it.Finally, the author reviews the main conclusions of the dissertation and elaborate theaspects of future study.