Research On The Openness Suitability Evaluation Of Closed Blocks

The closed block is the product of historical development.At present,the cost of urban land is increasing day by day,and problems are increasingly prominent such as insufficient road supply,crowded urban traffic and weak block vitality.Therefore,the government has issued a policy that the completed closed blocks should be gradually opened.The urban road planning concept of "narrow road and dense network" will be truly practiced.However,due to the difference in the location of the block and the nature of the land,the implementation of this policy should be tailored to local conditions.Therefore,this paper focuses on how to determine whether the internal roads in the block are suitable for opening in the existing closed block,and provide reference standards for the implementation of the policy.Firstly,this paper analyzes and summarizes the background of road-opening policy of closed blocks in detail and relevant practical cases in domestic and foreign cities,and then discusses the necessity of road opening of closed blocks.Secondly,based on the research results of a large number of literatures,the evaluation system of the suitability of closed block road opening is put forward from the two aspects of road network layout and traffic operation,land economy and social environment.Thirdly,considering the large number of evaluation system indicators,the analytic hierarchy process are obviously insufficient in determining the weights.Therefore,the weighting method based on genetic algorithm and analytic hierarchy process is proposed,and this method is compared with other weighting methods.Fourthly,based on the road network layout and traffic operation indicators,which are quantitative indicators,a grey cluster evaluation model based on genetic algorithm-analytic hierarchy process is proposed.For the land economic and social environment indicators,which are qualitative indicators,A fuzzy comprehensive evaluation model based on genetic algorithm-analytic hierarchy process is proposed.The final evaluation results are obtained by comprehensive evaluation of the two types of indicators.Finally,a case study was conducted in a closed block in Wuhan City,Hubei Province,and the method of evaluating the openness of closed blocks was applied.This paper proposes the evaluation method for the open suitability of the closed block.For the existing closed block to be opened,the suitability of the block opening can be evaluated accordingly,which provides theoretical support for the implementation of the block-policy.For the new block in the future,the standards of road network layout and other aspects can be determined accordingly,so as to provide reference for the new blocks.