The Theory And Method Of The Calculation And Optimal Integration To Network Transportation Capacity For Urban Transit System

With the progress of economics and standards of living, the configuration of transit network, the transportation capacity allocation and the planning of hub system are highly required due to the variety of demand and the development of transit system priority. The theory and method of the calculation and optimal integration to network transportation capacity for urban transit system is presented in order to avoid the limit of separate modal and line capacity planning. The theory could integrate resources for multi-modal. And it could analyze the allocation of functions for urban transit networks and the conformation of hub systems and the bottleneck of lines and stops for the capacity of transit system. The theory and method are studied for the supporting decision to improve level of service, the improvement and the development to the theory of transit system planning, and the complement and the advancement to the theory of transit priority. Furthermore, the development of intermodal transit system is the key for solving the problem of urban traffic. Especially, under the progress of economics and the fund deficiency for transit, the operation efficiency and operation quality of transit and the investment for target infrastructures should be evenly improved, which is an effective measure for integrating existing resources and avoiding the waste of blindly increasing investments.Firstly, the concept of network transportation capacity for urban transit system is presented by the theory and method of system science in this paper. According to the definition of network transportation capacity for urban transit system, the influence factors are analyzed, which include external environment, passenger demand mode, transit operation network, level of service, line capacity, stop and hub capacity.Secondly, according to the definition of transit network capacity, the theory for urban transit network capacity is divided to bus transit network capacity modal and intermodal transit network capacity modal. Bus transit network capacity modal and intermodal transit network capacity modal based on level of service are established by bi-level programming in term of network characteristic for transit system. And the heuristic method based on hybrid genetic algorithm with local search is designed and an example is computed to display the feasibility and the convergence of the modal and the algorithm.Thirdly, based on network topology for urban transit system, multi-objective modal of integrated optimization for urban transit network capacity is presented. The modal is extended to integrated optimization modals for urban transit network capacity based on demand satisfied and based on total cost limited in term of practical planning of urban transit. The combinatorial complexity of the solution is analyzed according to the conformation of the modal, which belongs to NP-hard problem.Furthermore, the idea of "integrated in macro plan, adjusted in micro plan" and the general frame of optimal integration for transit network transportation capacity are presented by a heuristic method which combines mathematic optimization and new idea of transportation planning in this paper. The results are planned by macro qualitative and quantitative planning for urban transit network as the primary foundation for micro adjustment. Adjusted procedures in micro plan are presented according to basic data, which include transit line adjustment based on regional function ranks, intermodal transit network assignment based on levels of path phases, and transit line capacity allocation based on complement strategies of quality and quantity, and the comparison of allocation costs is analyzed.Finally, the method of optimal integration for transit network capacity is tested by optimal itegration of transit network transportation capacity of shanhou district in Beijing.