The Study On The Transit Network Design Model And Its Algorithm

Urban transit system is the important part of the urban transportation. Urban transportation system planning will have a direct impact on the entire city transport system.. The reasonable layout of the public transport network and the reasonable allocation and scheduling is the core issue of the urban public transport. Therefore, the urban transit network design is a decisive component of public transport system. the urban transit network design determines the operating scope, the site distribution and the correlation between them, the level of service of the network. With respect to the fixed-line-based public transport system, the level of transit network design is the main measure of development of public transport, operating capacity and service quality. The main contents of the transit network design problem are through the choice of the transit routes and frequencies setting to achieve so that some kind of system performance of the entire network public is optimal system objectives. In fact, it is bound by certain conditions of the optimal investment decision-making and planning for optimal decision-making. Transit network design model is the entire public transportation network design foundation; the model quality impacts the quality of network design results.This thesis take the traditional transportation network design as a foundation, has analyzed the transit network design basis and the transit demand forecast, described the transit network which must study, has discussed the transit network integrant part and its function, and proposed the transit network design objectives, has analyzed influence factors of the transit network design and so on. It has analyzed the constraints of the transit network design problem, including headway feasibility constraint, load factor constraint, fleet size constraint, trip length constraint, maximum number of routes constraint and so on; And has constructed the cost function, including transit network user's costs and transit operating costs of the network. From the point of view of the minimum costs of the entire transit network, it has constructed the mathematical model of the transit network design problem. The method of simulated annealing algorithm is used to solve the model. Finally it has introduced a numerical example to validate the reasonableness and feasibility of the model constructed. This study proved that the transit network design model can be used as a reference for the city's transit network design, which overall goal is optimal social benefits, it has good values.