Research On Design Methods For Flex-route Transit Scheme

In order to alleviate traffic pressure,the government has given high priority to developing public transport,which makes the idea of public transport priority progressively being acknowledged.However,with the further development of urbanization and social economy,travel demands become diverse.Due to the constraints of operating cost and flexibility,conventional public transit can not serve these passengers well.Therefore,there is a need to enrich the mode of public transportation and improve the breadth and depth of public transit to better meet the diversified travel demands.Flex-route transit is a new transit mode,which combines the characteristics of conventional public transit and demand responsive transit.Flex-route transit has the advantages of flexibility and low cost.Although the flex-route transit has not been applied in China,it has a broad application prospect.To promote the development of the flex-route transit in China,this paper study design methods for flex-route transit scheme and carry out the research from the following 4 parts:1)After reviewing large amount of related literature in domestic and foreign,this paper clarifies the design process of the flex-route transit,discusses the early decision-making and later optimization of the flex-route transit,analyzes the decision-making framework of the flex-route transit,and determines what affects the design of the flex-route transit.2)On the basis of mastering the design flow of the flex-route transit,the operating characteristic and operation mode of the flex-route transit are further analyzed.At the same time,this paper carefully analyzes the influence of system elements on the flex-route transit,which supports the study on design methods for flex-route transit scheme.3)At the macro level,the cycle model,headway model and vehicle number model are established.The cycle model focuses on how to calculate the number of different passengers and how to calculate the running time of the bus.The headway model is deduced from the operating costs,the service quality and the maximum operating cycle.4)At the micro level,the main work is to improve the scheduling algorithm of the flex-route transit.After the analysis of the simple insertion algorithm,2 optimization algorithms based on rejection and reinsertion are proposed.One focuses on reducing the average travel time,the other concentrates on reducing rejection rate.This paper studies on the cycle,headway and scheduling of the flex-route transit,which can push the development of the flex-route transit in China,promote the establishment of integrated multi-modal transit,and improve the breadth and depth of the public transit service.