Research On The Transport-related Social Exclusion Mechanism And Process Of Urban Commuters Based On Spatiotemporal Behavior Differentiation

The primary objective of the urban transportation system is to facilitate access to specific locations within the city and enable participation in various activities for individuals in society.With the rapid progress of urbanization and motorization processes in China,as well as the changes in residents’ socioeconomic transformation and activity needs,there is heterogeneity among urban residents in accessing transportation resources across different social groups.Activity space is a comprehensive indicator of individual abilities and cognition that can reflect the bidirectional interaction between individuals and urban space.In recent years,transportation planners have attempted to address transportation-related social exclusion issues through the perspective of individual activity spaces,providing theoretical support for the establishment of an inclusive transportation system.However,existing studies on transportation-related social exclusion based on activity spaces lack consideration from the perspective of spatiotemporal resource allocation for individual activity-travel behavior and often treat activity space measurement indicators in an isolated manner.As a result,the enhancement of interpretability regarding activity space for transportation-related social exclusion at a micro-level,based on individual spatiotemporal behavioral differentiation,is a pressing scientific question that requires attention in social exclusion research related to transportation.This article utilizes the theory of time geography to introduce the concepts of fixity and flexibility,which forms the basis of the space-time prism and daily activity space.This method classifies activity space into constraint space and free space.The study then uses the 2016 Kunming residents’ travel survey data and a Logistic model to demonstrate the effectiveness of this method in recognizing transportation-related social exclusion.Furthermore,the study utilizes the concept of social-space dialectics to analyze the interaction between urban space and individual behavior from a horizontal and longitudinal perspective.Structural equation models are used to analyze the impact of geographic environmental backgrounds on individual time-space flexibility,while individual behavior changes in the process of urban space transformation are analyzed using a mixed time section approach.The main findings of this study are as follows:(1)Develop a set of indicators for identifying social exclusion related to transportation based on activity space.After structuring the activity space,it was found that an individual’s activity space consists of two parts of spatial resources: fixed and flexible.These were respectively defined as constraining space and free space.Comparing two logistic models with resident socio-economic attributes and built environment attributes as independent variables against the activity space model determined by the structure method of the activity space and the traditional standard ellipse method as the dependent variable,the coefficient of determination for the deconstructed activity space method was much greater than that of the models constructed by traditional methods,thus verifying that the activity space structuring method proposed in this paper has stronger interpretability in identifying transportation-related social exclusion.(2)When studying transportation-related social exclusion,it is essential to fully consider the dynamic issues related to an individual’s daily geographical background.The degree of social exclusion related to transportation can be measured by the intensity ratio of constraint space and free space,reflecting an individual’s spatiotemporal flexibility.Structural equation models were constructed to examine the impact of different geographical backgrounds and socioeconomic attributes on spatiotemporal flexibility through the mediation effects of daily activity and travel characteristics for the place of residence,workplace,activity place,and social economic attributes.The study found that the degree and path of the impact of the built environment on spatiotemporal flexibility vary for different geographical backgrounds.Specifically,the built environment of the place of residence has both significant direct and indirect effects on spatiotemporal flexibility,while the built environment of the workplace has only a significant indirect effect.The spatiotemporal flexibility is more significantly influenced by the built environment of the activity location,with the level of impact ranked in decreasing order as the residence location,workplace,and activity area.(3)The transformation of urban space has an impact on the social exclusion process related to transportation,and this impact comes from the enhanced demand for resident mobility.By constructing mixed cross-sectional data that controls for socio-economic attributes,a comparison of the activity-travel behavior of workers using different modes of transportation in Kunming in 2011 and 2016 reveals that urban spatial structure directly affects resident behavior.Specifically,suburbanization of residence stimulates the growth of automobile use rates,while dispersed activity locations lead to a shift in the transportation structure from slow to fast modes of transportation.In this process,the degree to which urban spatial structure constrains commuters using different modes of transportation varies.Overall,currently using automobiles has the function of reducing the impact of social exclusion related to transportation,and the behavioral differences between automobile travelers and non-automobile travelers are gradually widening.