Study On Key Methods Of Coordinate Optimization Between Rail And Bus

With the rapid development of China’s economy and urbanization process, asharp increase in the amount of city-owned vehicles. Traffic congestion, accidents,pollution and other environmental problems have become increasingly serious.Implementation of the "public transport priority" development strategy caneffectively alleviate the traffic problems in the city; improve the urban transportsystem environment to meet increasing traffic demands. Implementation of thestrategy should be to develop passenger transport mode which can play overall,guiding role in social and economic activities in the city and adapt existing supplycapacity of urban land resources, transportation infrastructure and environmentalcapacity status quo. Rail has been widely recognized because of its high rate ofpunctuality, large volume, comfort and energy saving, etc. To develop urban railtransportation, causing it plays a key role in urban public transport, and has becomea worldwide trend. In recent years, China’s urban rail transit investment continued toincrease resulting in the rapid development of rail transit construction. However, dueto the high technical requirements rail, big project investment, long constructionperiod, while the limited capacity of the national economy and local financialresources, many of cities short period of time can not form a complete rail networkoperators. Regular bus service as the main urban public transportation system is aneffective complements before the formation of perfect passenger transport networkof rail transport system. Mutual cooperation between the two services not only caneffectively increase rail traffic, and can achieve rail transit and bus complement andimprove the overall competitiveness of urban public transportation, and thus tooptimize the structure and purpose of urban residents travel overall layout. Therefore,based on the relationship of cooperation and competition between rail transit and bus,to promote the coordinated development of the two modes of transportation is anecessary requirement of the current development of urban public transport.Rail and Bus coordination optimization covers a wide, mainly through the integration of technology, line, management, policy, facilitie of these two modes oftransportation to implement share, cooperation and complementarity on the networkstructure and the transport of energy resources, thereby improving service levels andoperational efficiency of the entire transit system. It includes the coordination oftransfers between sites, network design, vehicle operation scheduling, ticket faresystem developed and management system. Considering the cost and technicalfactors, once rail traffic construction is completed, the line and station facilities isdifficult to adjust. Regular bus lines run based on road infrastructure; it can be makeadjustments in the short term according to the degree of change and demand ofpassenger of lines. Therefore, this paper studied conventional city bus stationoptimization, network design, operations coordination, emergency transport andother issues under rail transportation planning or completion condition.Relying on the National Natural Science Foundation of “Research on Publictransit network generation optimization model and algorithm based on the networktopology and traffic congestion（51378237）”, this paper studied conventional bussystem optimization problem under the context of the rapid development of railtransport based on the domestic and foreign research. Four models were established,include station optimization in local transfer network of rail transit and bus, feederbus network design model based on effective path, Bi-level programming model forcoordinated operation between urban rail and bus systems, bus emergency transportmodel under rail emergencies. The completed research results are as follows:1. To improve the transfer efficiency of local network including rail transit andbus station, local transfer network was described and a reasonable network size wasdetermined. Considering the capacity of the station and station spacing as theconstraints, optimization model was established to minimize the travel cost andmodel algorithm was proposed based on community structure of complex network.The model is applied to local transfer network including some station of ChangchunLight Rail No.3and bus stations around it. The results show that the overall transferefficiency of the local network can be increased by16%, and total system costs canbe decreased by6.16%considering the case of the time value.2. The effective connection between urban rail and bus is a very importantaspect to coordinated development of the public system. The two-target model basedon effective path was established to solve feeder bus network design problem(FBNDP). Firstly, effective path concept is defined on the basis of complex networkbetweenness considering urban traffic congestion, which is the basis of feeder bus network design. Taking into account the constraints such as line length, non-linearcoefficient, transport capacity etc., the two-target model was established by takingthe minimization of passenger travel time and maximizing transport efficiency as thetarget. Then referring to “Combining Each Route, then Form the Network”, thesolution approach to the model was proposed. Finally, the model is applied to theLRT4of Changchun and the results show that the model can reduce passengerwaiting and transfer costs effectively. The results show that feeder bus networkdesigned by the model in the presence of traffic congestion can reflect residentstravel selection strategy better.3. The coordinated operations of urban rail and bus systems are an importantpart of coordinated development of the public system. A Bi-level programmingmodel for optimizing the headway was established in order to achieve coordinatedoperations between them. Firstly, the coordinated operations of urban rail and buswere described. Based on the analysis of system cost, the upper-level model wasestablished by taking the minimization of the total cost of the operation system as thetarget. An improved model of optimal strategy selection was used as the lower-levelmodel to assign transit trips to bus route network based on optimal strategy. Then,solution step of the model was proposed combined with genetic algorithm andlabel-marking method. Finally, the model is applied to the urban rail and bus ofChangchun and the results show that the model can reduce passenger waiting andtransfer costs effectively.4. Emergent events in urban rail transit threaten the safety and order of thenetwork, and seriously affect the normal operation of the rail system and residentstravel. The evacuation and transport of rail passengers using bus in emergencyevents is an effective method to maintain the entire order of the urban passengertransport system. Therefore, emergency strategy of regular bus under emergencycircumstances of rail was studied in this article. Firstly, the affected passenger trafficwithin the public transport network and the emergency bus passenger transport weredetermined. Secondly, considering the randomness of emergent events, theemergency line design model was established taking the shortest travel time andtransport efficiency maximum as target, and gives a model for solving steps. Finally,simulated emergencies at Changchun rail, the traffic matrix and the public transportnetwork as an input; the emergency lines have been designed and the relevantindicators were calculated. The results show that under capacity constraints,emergency transport line can effectively reduce the stranded passengers travel delays.The results of this research can rich urban public transport planning theorysystem, improve the coordinated development between urban rail transit and bus atthe site, network, operations, emergency and other aspects, promote the healthy andorderly development of the urban public transport system, have high theoreticalvalue and practical significance.