Evaluation Of The Public Transport Service Based On The Spatial Equity Theory

The current public transport evaluation system mainly focuses on the indicators concerning service capacity and efficiency.Most public transport development programs only treat the concept of equality or fairness of the public transport system as the general guide.Very few specific evaluation indexes of service equity are involved in the practical evaluation.This distinct gap between certain policies and concrete practices has an obvious cause,i.e.,three key research points are still needed to be carefully exploring: what is the core object of the equity evaluation of the public transport system? What kind of equity theory can act as the guideline of equity evaluation? What is the equitable situation?In this paper,the public transport service is chosen as the core object of the evaluation research.Based on a detailed exploration and explanation of the internal relationship between two service measurement models(i.e.,the service intensity measurement model and the accessibility model),corresponding spatial equity evaluation methods are constructed in terms of the spatial characteristics of the two models.After this,an evaluation method concerning the time-varying trend of the spatial equity is constructed in terms of carefully detecting the characteristics of the proposed spatial equity evaluation methods and rules.Considering all these approaches,this dissertation finally completes the establishment of the spatial equity evaluation system,which in return helps to realize the comprehensive evaluation of the spatial equity of the public transport service.This paper constructs a spatial equity evaluation method for the measurement model of the public transport service intensity.In the first place,by Incorporating the core idea of the kernel density estimation theory,a measurement model of service intensity is proposed.Based on the calculation results of this model and the distribution of residential population,a corresponding spatial equity evaluation framework is introduced.The evaluation framework involves two steps,i.e.,the local scale and the global scale steps.In the global scale steps: a new SE index,which is constructed in terms of the Gini coefficient and Moran index,is proposed.This new index which combined the egalitarian-based equity evaluation with the spatial analysis can carry out an overall assessment of the case study.In the local scale steps: the spatial gap analysis which thoroughly detects the coupling relationship between the demand and supply of bus services is introduced.This method also acts as the local scale explanation of the result of the global scale analysis.The case study of Shenzhen implies that:(1)The SE index shows that the administrative districts with the best and worst spatial equity status are both located in the downtown area of the city,which are the Nanshan and Luohu districts;(2)The local scale evaluation visually displays the demand and supply gaps and matching status at each analysis unit.The results indicate that there exist limitations in the single-use of the Gini coefficient when conducting bus service evaluation,i.e.,the same or close Gini coefficients can correspond to completely different coupling relationships between the demand and supply of the public transport service.An appropriate spatial equity evaluation method concerning assessing the spatial equity of public transport accessibility is also introduced.To achieve this approach,a spatial accessibility model of the production-living-ecological space is proposed.This model is constructed with the datasets including the urban land use dataset of Shenzhen,and the big data of commuting time and corresponding expense cost crawling from the web service API of the Auto Navi Map.On basis of this model and the core equity theory of the Capacity Approach,several systematic evaluation rules which evaluate the spatial equity of the public transit accessibility from three aspects,i.e.,evenness,sufficiency,and efficiency aspects,are put forward.The main results are as follows:(1)The overall public transit accessibility of the production space is relatively even,while the ecological and living space accessibility presents an apparent trend of agglomerating in the downtown area;(2)Under the average commuting cost restrictions,there is no distinctive public transport deprivation phenomenon in the central urban area,whereas seriously transit deprivation phenomenon can be spotted in some areas located in the Guan Wai area of Shenzhen;(3)According to three systematic evaluation rules.The spatial equity of the public transit accessibility of Futian District is relatively good.The public transport system in this area provides even and efficient travel services,with which the residents in this district can avoid suffering from the deprivation of the public transport.Finally,this paper constructs an evaluation model concerning the time-varying trend of the spatial equity of the public transport service.This evaluation method is proposed by carefully exploring the characteristics as well as the differences between the two evaluation methods introduced for the two measurement models of the public transport service.The time-varying analysis of SE index,statistical methods(i.e.,the descriptive statistics and inferential statistics methods),etc.are carried out to appraise the time-varying trend of the spatial equity relationship between the distribution of the demand of services(i.e.,the distribution of residential population as well as the transport disadvantaged groups)and the distribution of the public transport service in terms of the opening and operation of new subway lines.The main findings are as follows:(1)The spatial equity relationship between the distribution of residential population and the distribution of the service intensity only gets improvement in a very limited way;(2)The operation of new lines did not optimize the spatial equity relationship between the distribution of disadvantaged groups and the distribution of the service intensity;(3)Based on the evaluation rules towards the timevarying trend of the public transport service,only the spatial equity of the accessibility of the living space gets improved;(4)The public transport accessibility of areas with more disadvantaged population residing in is better than other areas,and this phenomenon get improved in the background of the operation of new subway lines.According to the results of the equity evaluation,specific policy recommendations are discussed from four aspects,i.e.,(1)Involving in the consideration of the equity concept in the promotion of the construction of the public railway transport system;(2)Promoting more residential opportunities in terms of the actual situation;(3)Optimizing the spatial layout of the job opportunity,parks,etc.;(4)Optimizing the connection efficiency between public bus system and railway transport system.Finally,on the basis of summarizing the characteristics of the established spatial equity evaluation system,practical evaluation suggestions for proposed evaluation indicators and methods are given so that they can be better employed in actual work.