Research On The Integrated Planning Of Demand-responsive And Fixed-route Local Bus

To achieve sustainable development,it is necessary to vigorously develop public transport and implement the public transport priority strategy.However,conventional public transport still has shortcomings such as low service quality and poor operating efficiency,which cannot meet the personalized traffic needs of residents.Demandresponsive transit is a new operation mode between conventional bus transit and taxi.It has the advantages of being people-oriented,convenient,fast,and economical.Therefore,it is necessary to develop demand-responsive transit and combine it with fixed-route transit to give full play to their advantages and further improve the efficiency and LOS of the public transport system.Starting from the issue of integrating the demand-responsive and fixed-route transit,this study mainly answers the following two questions: on which level of the public transport system to implement the integration,and how to implement the integration.The main contents and conclusions are as follows:1.The functional localization analysis of demand-responsive transit.This study summarizes the concept,system composition,functional characteristics,operation and service mode of demand-responsive transit,and further analyses urban multimodal transit’s functional hierarchy and network layout.The conclusion is made that the most appropriate role of demand-responsive transit is to serve as local feeder buses,because it has the advantage of high service quality and being economic and efficient.At this level,the integration of demand-responsive and fixed-route transit can improve the LOS,efficiency and operation safety,while reducing costs.2.Modeling and analyzing the demand-responsive and fixed-route transit.The demand-responsive and fixed-route local bus are modelled and analyzed respectively,and the relationship between the LOS of two transit operation modes and the system parameters and passenger flow is analyzed.The results of comparative analysis show that given the same number of buses,when the travel demand density is small,the demandresponsive transit will have better LOS than the fixed-route transit.With the increase of demand density,the LOS of demand-responsive transit will decline.After reaching a certain critical demand density,the LOS of demand-responsive transit will be lower than that of fixed-route transit.Agencies can choose the most appropriate operation mode at different time periods according to the change of passenger flow conditions in a day3.Methodology to integrate the two operation modes and the optimization The integrated layout of different modes of local buses in the area with large aspect ratio and small aspect ratio is proposed respectively.The concept of user equilibrium is introduced to solve the problem of division of service areas relating to different mode.The example shows that the integrated layout mode can significantly optimize the LOS of public transport system in the area with small aspect ratio,while the optimization effect in the area with large aspect ratio is poor.In order to further select the optimal layout scheme from multiple ones that meet the equilibrium conditions,an optimization model is established and a genetic algorithm is constructed to solve it.4.Empirical Study.Taking the Chongqingdong Railway Station as the empirical analysis object,the integrated layout planning of demand-responsive and fixed-route transit is carried out.The results show that the optimal integrated layout scheme can improve the LOS of bus system massively.Passengers’ travel time in the integrated planning decreases by 32% compared with the fixed-route single mode and 36%compared with the demand-responsive single mode.Further analysis revealed that deploying the integrated planning will lead to a rise in vehicle traveled miles,about 85%above from the fixed-route single mode and 28% above from the demand-responsive single mode.