The Accessibility And Fairness Analysis Of Bus Connections At Subway Stations With Uncertain Travel Time

With the continuous acceleration of urbanization and motorization,the traffic problems in big cities become more and more obvious day by day,which affects the fast development of our national economy,and brings great challenges to people’s quality of life and advancement of urbanization.In order to alleviate the rapidly growing demand for urban transport,the public transport-oriented urban development mode promotes the high-density construction of urban public transport facilities.However,it is the fundamental direction of the development of public transport to establish public transport services with good accessibility and fairness from the perspective of travelers.As the main body of urban public transit system,conventional bus has the advantages of flexible route layout,wide coverage and good accessibility.It is one of the main connecting modes around rail transit stations.However,connecting bus faces many problems,such as low reliability of travel time,unbalanced distribution of line network and serious difference between supply and demand.Therefore,by building an accessibility model,studying the accessibility differences of different stations,identifying the weak service areas where subway stations connect to buses,analyzing the sensitivity of accessibility of different stations to travel reliability,and finding out the crux of the difference in bus distribution is the key to fundamentally improve the level of public transport service and enhance the attractiveness of public transport system.In this paper,the characteristics of bus operation are analyzed,and the influence of travel time uncertainty factors on accessibility is studied.At the same time,huff model is used to measure the competition between stations.On this basis,this paper establishes an accessibility measurement model based on station service efficiency,and analyzes and compares the accessibility of existing subway feeder stations.Secondly,on the basis of the existing accessibility measurement model,the historical travel time between stations was extracted by using the bus GPS data,and then the probability distribution function of the travel time between different stations was obtained.The accessibility measurement model under the reliability constraint was constructed,and the sensitivity of the accessibility of different bus stations to reliability was analyzed.Finally,the Gini coefficient is used to evaluate the accessibility of subway stations and the equilibrium degree of supply and demand ratio of connecting lines.The influence of reliability on the accessibility of different subway stations and the Gini coefficient corresponding to the supply and demand ratio of connecting lines is studied.In order to find out the crux of the serious imbalance in the supply and demand ratio of connecting routes,this paper divides regions according to the accessibility of stations,and uses the decomposition of Gini coefficient to obtain the grouped Gini coefficients of different regions and their contribution to the Gini coefficients,which provides theoretical support for the equity-oriented optimization of public bus network layout and improvement of bus planning and operation management.