Optimization And Regulation Of Urban Traffic Structure Under Carbon Emissions Reduction Target

Together with fast economic growth and continuous improvement of motorization degree,urban transportation carbon emission problems become increasingly prominent.There exists great difference between different traffic modes in terms of energy consumption and carbon emission.Traffic structure is the key factor that affects urban traffic carbon emission.As the main low-carbon emission reduction department,the transportation department has the responsibility to promote the innovative development of urban traffic system,transforming to be a modern urban transportation system with high efficiency and low carbon on the basis of the optimization of urban traffic structure.At the meanwhile,the transportation department has been constantly improving the urban traffic function and meeting the travel needs of residents.How to improve urban transportation development mode,reduce the proportion of high carbon emissions travel modes and guide urban traffic low-carbon development on the basis of meeting residents’ travel needs is an important research topic to be observed and also a severe challenge confronted by urban low-carbon construction.The paper performs a research on urban traffic structure optimization model,realization path and regulation policy under carbon emissions reduction target.The research begins with the evolution process of urban transportation development mode,observes the interaction between internal composition and external system of urban transportation system,and constructs urban traffic structure optimization model under carbon emissions reduction target based on multi-target planning thought.This model applicable for the research of traffic structure optimization in different cities and has strong universality.Meanwhile,the model fully considers the coordinated development of urban transportation system,economic system,social system,environment system,resource system and policy system,and creating seven objective functions comprising carbon emissions,external cost,energy consumption,financial subsidy,road network efficiency,travel cost and travel quality.On this basis,the research respectively starts from the perspective of carbon emissions reduction target and carbon emissions reduction satisfaction to observe carbon emissions reduction effects of urban traffic structure optimization.Through directly analyzing the carbon emissions reduction target realized by urban transportation structure optimization by absolute amount,and objectively analyzing the actualization difficulty of urban transportation carbon emissions reduction target in different transportation conditions and external environment conditions by relative amount,the model helps clarify urban carbon emissions reduction potentials and formulate proper carbon emissions reduction target.Afterwards,it designs urban traffic structure optimization path from the perspective of traffic management,traffic resource,traffic technology and land use,quantitatively analyzes the optimization results of all paths,and eventually ascertains the best optimization path of urban traffic structure optimization under carbon emissions reduction target.Moreover,it describes the dynamic optimization process of urban traffic structure under carbon emissions reduction target.Furthermore,in combination with the demand analysis on diverse optimization path policies,it designs urban traffic structure optimization policy system under carbon emissions reduction target.This policy system designed according to reverse deduction thinking integrates with policy effect quantitative analysis results and regulates policy content,implementation sequence and implementation force.Such policy design method ensures the scientificity and effectiveness of traffic structure optimization policy system under carbon emissions reduction target.Finally,the paper takes Shanghai as an example to carry out case analysis,and proposes several pertinent policy suggestions for urban traffic structure optimization under carbon emissions reduction target,so as to provide reference for promoting the development of urban low-carbon traffic.Here list the main contents and conclusions:(1)The paper constructs an urban traffic structure optimization model under carbon emissions reduction target.The paper respectively chooses traffic carbon emission,external cost,energy consumption,travel cost,road network efficiency and travel quality as urban traffic structure optimization targets,determines traffic supply factor,traffic demand factor and external environment factor as the influence factors of urban traffic structure optimization,and builds optimal urban traffic structure model under carbon emissions reduction target.Moreover,it converts the model to satisfaction function model.The traffic structure with maximum sum of satisfaction of all optimization targets is the optimal value of urban traffic structure.The higher the target satisfaction,the closer the actual value is to the optimal value under current traffic conditions and external environment as well as higher attention on the target in urban system development process.(2)The paper conducts a potential analysis on urban traffic carbon emissions reduction.The increase of carbon emissions satisfaction would give rise to the change of other optimization targets with varying degrees.As revealed by the research results,it is difficult to achieve traffic carbon emissions reduction target by simply regulating urban traffic structure but remaining existing traffic conditions and all traffic parameters unchanged.The feasible practice is to improve existing traffic environment on the premise of effective resource allocation,traffic technology progress and scientific urban planning,and optimize urban traffic structure on the basis of parameters regulation,therefore achieving carbon emissions reduction target and possibly maintaining the satisfaction of other targets.(3)The paper takes Shanghai as the example to perform a comparative analysis on urban traffic structure actual value and optimal value under carbon emissions reduction target.As indicated by urban traffic structure optimal value in Shanghai,the optimal proportion of rail transit is 61.75%,significantly higher than actual proportion as 34.17%;the optimal proportion of ground bus is 19.73%,slightly lower than actual proportion as 21.26%;the optimal proportion of tax is 4.21%,lower than actual proportion as 10.85%;the optimal ratio of private car is 14.31%,significantly lower than actual proportion as 33.72%.As a result,rail transit should be the mainstream travel mode in Shanghai,private car travel proportion should be greatly lower than present level,ground bus should maintain existing travel proportion,and taxi travel proportion should be slightly decreased.Corresponding variation of carbon emission target value indicates that,in existing traffic environment of Shanghai,structural adjustment of urban traffic system may realize 47.62% traffic carbon emissions reduction target.Additionally,the satisfaction of all targets illustrates that the urban traffic development of Shanghai is subject to maximum influence of micro-individual travel experience,including comfort degree and travel cost.Meanwhile,financial subsidy also plays a vital role in the formation of urban traffic structure.Rare attention has been paid to carbon emissions and energy consumption.(4)The paper takes Shanghai as the example to perform an analysis on urban traffic structure optimization path under carbon emissions reduction target.Throughout the comparison on the optimization effects of various optimization paths,it can be found that the best three optimization paths are traffic management and traffic resource dual-regulation(G&Z),traffic management and land use dual-regulation(T&G)and singular traffic management regulation(G)with respective carbon emissions reduction target as 27.85%,27.75% and 23.78%.From the type of traffic parameters,traffic management parameters have the best optimization effects on urban traffic structure and carbon emissions in Shanghai,and traffic management parameters should be the key regulatory object of urban traffic structure optimization.Moreover,full-factor optimization path(T&G&J&Z)has poorest optimization effects,but increases carbon emissions by 8%.It means that the simultaneous implementation of multiple traffic policies is likely to offset the optimization effect of some policies.(5)The paper takes Shanghai as the example to design urban traffic structure regulation policy system under carbon emissions reduction target.As revealed by urban traffic structure optimization results in Shanghai,the prime regulation content of traffic policy is to expand public transportation scale and improve individual motorized travel threshold.In particular,traffic management and traffic resource regulation policy should be executed in priority,traffic technology and land use optimization path must be planned in advance and executed in the long run.As proved by the quantitative analysis on traffic policy effects,public traffic routes regulation policy has significant optimization effects on urban traffic structure and carbon emissions reduction target in Shanghai,and optimization effects show “S”-shaped changes with the extension of public traffic route.The optimal policy execution force is to improve public traffic route scale by around 15%-20%.This policy regulation scope can not only promote the significant optimization of Shanghai urban traffic structure,and realize 20% carbon emissions reduction target,but also ensure the full use of traffic resources.