Evaluation Of Urban Traffic Accessibility And Equity Based On Multi-source Big Data

Equity and justice are becoming issues of common concern to various countries around the world,and the construction of The Transit Metropolis has become the goal and vision of sustainable development of global cities.The main contradictory changes in China’s society in the new period point to the inequity that exists in our society at this stage,which manifests itself in the field of transportation as the contradiction between the need of urban residents for a good transportation environment to meet travel needs and the unbalanced development of urban public transportation.Under the background of this era,the development strategy of a transportation powerhouse has been proposed,and it provides a direction for advancing the priority development strategy of public transportation and promoting transportation equity.At present,the accessibility evaluation model is relatively mature.It is roughly divided into three categories: the accessibility model based on space barrier,the accessibility model based on opportunity accumulation,and the accessibility model based on spatial interaction.Equity evaluation models are more likely to introduce cost-benefit,income distribution models and other models in the field of economics for evaluation.The equity and accessibility research perspective covers a wide range of fields including geography,economics,sociology,and management.Based on the time cost perspective of transportation,this paper evaluates the accessibility and equity of public transportation and car transportation in the centralized construction area of Kunshan City.The accessibility model takes the spatial barrier model as the base model,the meaning of which is the time barrier of travel.The method is simplified and optimized using new technologies and new data in the method.The equity model takes the cost and distribution ideas as the starting point,and its meaning includes three aspects: transportation mode equity,individual equity and spatial equity.The research methodology explores transport equity using models such as the Bus Competition Index,the Gini Coefficient and the Thiel Index.Finally,based on the results of the study,specific implementation recommendations for the optimization of the accessibility and equity of the centralized construction zone in Kunshan City.The results of the study indicate that:(1)In the same zone,the accessibility of public transportation is generally lower than that of cars.The travel time cost of public transportation is generally higher than that of car transportation,and the average travel time consumption is about three times that of a car.Therefore,Kunshan City’s public transportation is not competitive enough,and it is in a weak position in the transportation mode structure.Inconsistent,the relevant government departments and managers should consider reducing the accessibility gap between public transportation and car transportation by suppressing cars,promoting public transportation and other specific planning and management measures,and practicing the development concept of public transport priority to promote urban sustainable development.(2)The accessibility of public transportation is spatially decreasing from the central city to the periphery,and the accessibility of cars is the opposite.From the perspective of the accessibility distribution of the same transportation mode in different spaces,the public transportation accessibility presents a spatial distribution of high peripheral areas and low urban core areas.The accessibility of cars is spatially opposite to public transportation.The accessibility level near the city’s core area is low and gradually increases toward the periphery.This is related to the built environment of the city’s core area and traffic congestion during the morning peak.To a certain extent,this spatial distribution of accessibility has restrained the travel mode of cars entering the core area.(3)Public transport priority is a substantial measure to promote traffic equity.The Gini coefficient of car transportation is greater than that of public transportation,and the Theil index of car transportation is greater than that of public transportation.The evaluation results of both methods are that the equity of public transportation is better than that of car transportation.Therefore,increasing the sharing rate of public transportation is a substantial measure that can promote traffic fairness.It can also be seen from the comparison of the results of the two equity evaluation methods that the Theil index is sensitive to the Gini coefficient when calculating the equity,and the difference in the Theil index between the regions is greater than that of the Gini coefficient.(4)Traffic equity presents a situation where the center is high and the periphery is low,and the accessibility gap of the base station unit is the main reason for inequity.The equity gap of cars in various districts is not big,and the equity gap of public transportation is more obvious than that of cars.From the decomposition of the Theil index,the contribution of the Theil index within the group is much greater than the Theil index between groups.Therefore,the reason for the inequity is the difference in accessibility between the base station units.In the planning and management process,we must pay attention to the full coverage of traffic resources balances the reachability of base station units within the control unit.This paper uses multi-source big data to optimize and simplify the accessibility evaluation model,which is embodied in two aspects: firstly,the use of dynamic traffic data to simulate the travel trajectory;secondly,the use of mobile phone signaling data to carry out population weighted average of the travel cost.In the equity evaluation,the Gini coefficient and Theil index evaluation methods in the field of economics were introduced,and a useful exploration was made on the integration of disciplines.However,there are also deficiencies in this article,including insufficient consideration of other factors in accessibility evaluation,inadequate human-centered thinking in equity evaluation,and lack of evaluation criteria for related indexes.These are the directions that need to be deepened in the future.The whole thesis contains about 42 000 words,61 pictures and charts.