Calculation Of Operating Efficiency Of Bus Stops And Optimization For Dwelling Scheme Of Buses

The optimization for dwelling scheme of buses is an important part of the urban transportationplanning and management theory. And it is an effective way to improve the operating efficiencyand service level of public transit. In recent years, with the rapid development of public transport,bus stops face increasing pressure especially during peak hours and serious traffic congestionoccurs frequently, which decrease the service level of public transit.The fundamental reason for the above problems is that bus demand exceeds the capacity ofthe bus stops, resulting in some buses waiting in the travel lane until the buses occupying the berthentrance. There is an urgency to systematically study and assess the operating features of bus stops,which will provide basis for detailed planning and management of bus stops and bus operation.Therefore, in view of the shortcomings of current studies on the calculation of operating efficiencyof bus stops, this paper conducted the related studies on the characters of bus operating at stops,the regional traffic characteristics affected by stops, the calculation of operating efficiency, andthe optimization methods for dwelling scheme of buses aiming at the current status of the bus.Finally, a systemic and scientific subarea partition system is developed. The main research workand production completed in this paper are summarized as follows.(1) The characters of bus operating at stops and traffic characteristics of regionalaffected by stopsThe function of bus arrived at stops is analyzed from the point of theory and probabilitystatistics. The calculation model of dwell time is calibrated using the actual survey data, and itsprobability distribution functions is fitted. The vehicle operating characteristics is analyzed withinbus influence area for each type of bus stop. On this basis, a method of computing the capacity ofroadway links is developed using queuing theory and gap acceptance theory, and the validity ofthe models are verified by VISSIM simulation.(2)The calculation of operating efficiency of bus stopsThe servicing process of buses is analyzed at the on-line stops with the trajectories aiming atthe current status of the bus. On this basis, the method of computing on-line bus stop and bus baycapacity are developed, which considers both the queue probability, the dwell time distributionand the time of waiting for a gap in the traffic stream at the curb lane. The queuing model of busstops are analyzed, and the equilibrium distribution function are proposed by using the embeddedMarkov chain and Z-transform method to the traditional model of queuing theory in the steadystate. The calculation models of bus delay and queue length are derived at stops and bays. Finally,the proposed models are validated using field-measured and simulated data. With these models thecapacity and delay gain are easily assessed knowing the characteristics of the dwell timedistribution, the queue probability and traffic volume at curb lane in different locations anddifferent periods. It can provide basics for the efficiency evaluation of bus stops. (3) The optimization methods for dwelling scheme of busesFor the actual situation of different bus stops, the measures of improving operating efficiencyare studied from two aspects of decreasing supply efficiency and reducing demand frequency. Atthe respect of decreasing supply efficiency, the bus line assignment model to divided dual-berthstops is developed. At the respect of reducing demand frequency, the single line bus skip-stopoperation optimization method firstly is studied in order to separate different passengers of travelO-D, and then the multi-line bus skip-stop operation optimization method is proposed with thegoal of easing congestion of stops. At last, the Tian-mu-shan Road of Hangzhou city is used as anexample. The bus line assignment program, single line bus skip-stop operation scheme and multi-line bus skip-stop operation scheme are designed respectively used proposed methods. Resultsshow that the optimization scheme can improve the operating efficiency of studied road.At last, the research contents in this paper are concluded and the innovative points aresummarized. Then the shortcomings of correlation degree models are analyzed and the followingresearch plan is provided.