Study On Real-time Dispatching In Public Transit Basing On Stochastic Chance-constrained Programming

Rapid socio-economic development,enlarging urban scale and increasing number of motor vehicles,especially private cars,make a serious shortage of transport supply and traffic congestion becomes even more serious.Development of the city depend more on the rapid passenger transportation system,and more requirements are put forward to the urban public transport operations and managements.Urban public transport system scheduling has become an important issue of transport development. The traditional urban public transport operations,with no real-time passenger flow consideration,are inefficient and severely restrict the development of the city.Therefore it is an urgent issue as to making use of modern technologies in urban public transport to refine the present vehicle dispatch operation,improve the service of urban public traffic system to meet the demands of the growing urban passengers.The gradually maturing GPS positioning technology,GIS technology,communication network technology as well as computer technology makes it possible to build a dynamic, real-time regulated urban public transport operating system.To this end,based on bus schedule analysis and dispatching design,we analyzed the methods to determine timetable in the case of stochastic passenger flow,designed real-time bus dispatching plan and validated it with the data from the express bus line 919 of Beijing Public Transport Company.The major works are described as follows:1.Based on analyzing passenger flow history data,the first and last dispatching time,departing intervals is determined;2.A random chance-constrained programming model is constructed in respect of the mutual interests of both transport companies and passengers.The model uses penalty fee as object function and describes the congestion degree and expected load factor by chance constraint to determine the departure intervals of each period;3.Real-time dispatching control of moving buses through information collected from devices in APTS.Established a reasonable scheduling method to make the delayed buses to return back to schedule as soon as possible;4.Finally,the rationality and feasibility of the theories is exemplified which obtained good results.