Transit Network Capacity Flexibility Evaluation And Adjustment Strategy

With the rapid development of cities and in-depth implementation of bus priority strategy, the contradiction between supply and demand of the transit system is prominent, and there is more attention on how to solve the problem of the contradiction between supply and demand and promote the transit system balance of supply and demand in transit schedule. However, current researches for the contradiction between supply and demand of public transport system are not enough in depth from the perspective of transit network capacity, and the relevant quantitative evaluation methods are not reasonable enough, it can’t reflect the root cause of the problem from the aspects of supply capacity. Therefore, mining the relationship between capacity and passenger demand, finding a scientific and effective evaluation index fro, the perspective of public transit network capacity supply and passenger demand are very important.This paper introduced the flexibility theory which is widely used in the areas of manufacturing and supply chain, combined with the theory of public transportation network capacity, it evaluated the coupling relationship between supply and demand of public transport system from the perspective of flexibility which facilitated transport system to suit the remedy to the case and schedule the scheme which accords with common interests between passengers and bus companies. It has defined the related definition of transit network capacity, discussed the composition and influence factors in detail, and analyzed the concept of flexibility, combined with the flexibility theory and the characteristics of transit public capacity to put forward the concept of capacity flexibility. It has detailed analyzed the capacity flexibility from dimensions and classifications.It has paid more attention to studying the three dimensions of scope, time for transformation and cost for transformation based on the flexible capacity theory as well as the synthesis of the concept of dimension and classification, analyzing the index that can reflect the dimensions and considering the passenger and the interests of the public transport system at the same time. It has established the flexible capacity performance index and potential of the flexible capacity index from the aspects of buffered flexibility and adaptive flexibility. It considered the existing performance evaluation indexes of the transit system to determine the level of the flexibility degree index, and analyzed the necessity and rationality of the evaluation for the capacity flexibility.This paper constructed the overall capacity calculation model and the used capacity scheduling based on the flexible adjustment strategy model. The former mainly considered the public transit system level to calculate the overall capacity and the latter considered the passenger route choice and the public transit system level at the same time, with frequency and load factor as the key decision variables, which calculated the using capacity and related scheduling parameters after flexible scheduling adjustment. Then it solved flexibility degree model. It solved the lower model which reflected the passengers route choice based on the Logit loaded SUE model, while using genetic algorithm to solve the upper model which reflected the transit system level. Moreover, it simulated transit network according to actual condition, and it combined with the instance to solve flexibility degree of model, as well as analyzed the results. Finally it put forward the model validity analysis and sensitivity analysis of related parameters.