Study On Accessibility Of Urban Public Transit Based On Smart Card Data

With the acceleration of urbanization,urban traffic congestion has become increasingly serious.It has become a hot issue of concern in urban construction and development.As the backbone of urban transit system,urban public transit is the main mode of transit for daily travel of urban residents.Giving priority to the development of urban public transit is the primary principle and fundamental guarantee for relieving urban traffic congestion.Accessibility is an important reflection of the interaction among the transit system,urban land use and travelers.The fundamental purpose of public transit development is to improve accessibility.Therefore,accessibility,as an important performance index of public transit,is of great significance for the development of public transit.How to understand public transit accessibility and put forward scientific and reasonable research methods is the key point for the study of urban public transit accessibility.The rise of big traffic data has provided a new perspective for the study of urban traffic problems.The data accumulated in the urban public transit operation process provides an opportunity for the analysis of urban public transit accessibility.First,the smart card data(bus IC card data and metro AFC data)is preprocessed to provide good data preparation for subsequent research.Secondly,through matching and analysis of bus IC card data and metro AFC data,a reasonable transfer time threshold is determined.Then passenger's travel information on the entire public transit network can be discovered by constructing complete travel processes based on transfer identification.Based on the actual travel of passengers in the public transit network,the dynamic travel distribution of public transit is obtained.And the travel time of public transit is modeled and determined based on the passengers' travel modes.Then,the time-varying characteristics of demand and attraction are pointed out based on the analysis of the internal relationship between dynamic travel distribution and destination attraction.Combining the influential factors of public transit accessibility,the passenger distribution and travel time are selected as basic elements,and a data-driven accessibility measurement is constructed based on the traditional model,which mainly includes a time-space probability model and an improved cumulative opportunities model based on passenger actual travel.Thus the public transit accessibility research method is proposed based on smart card data.Finally,taking Beijing as an example,combined with actual data,the spatial temporal distribution characteristics of public transit accessibility are analyzed,and ArcGIS software is used to visualize the results.The results show that there are large differences in accessibility at different times and regions.It is thus pointed out that the dynamics of demand and attraction and the level of public transit service are fundamental reason of the spatial and temporal distribution characteristics of public transit accessibility.