Research On Vulnerability Assessment And Improvement Strategies Of Urban Road Network From The Perspective Of Transportation Supply And Demand

The urban road network is an important lifeline that supports social and economic operations.However,the large-scale failure of the road network caused by frequent emergencies in recent years has fully exposed the vulnerability nature of the road network,and has also made the research on the vulnerability of the road network a research focus.The current research on the assessment and improvement of road network vulnerability focuses on the unilateral perspective of transportation supply such as network structure and network operation,while ignoring the root cause of transportation demand,that is,the impact of land use spatial layout.In order to more comprehensively evaluate the vulnerability of the urban road network,explore the root causes of the road network vulnerability,and improve the vulnerability of the road network from the roots,this study combines the perspective of transportation supply and demand,and takes the main city of Wuhan as the research scope to develop the road network Vulnerability assessment and improvement strategy research.First,based on the mobile phone signaling OD data,Trans CAD is used to perform traffic allocation under the User Equilibrium conditions,allocating road network transportation demands;relying on Matlab to build a demand efficiency-oriented vulnerability assessment model,calculating the amount of the average travel time change in the network before and after the failure of each unit segment to assess the vulnerability of each section.Secondly,construct a logistic regression model to quantitatively analyze the correlation between road network vulnerability and land use and transportation elements,and explore the root causes and dynamic mechanism of road network vulnerability.Finally,superimpose real-time road condition data to identify road sections and areas that are prone to congestion and have a greater impact on the efficiency of the road network,provide a hierarchical classification basis for spatial planning management,and propose specific improvements strategy to road network vulnerability.The results of the study show that the expressway and cross-river bridges in Wuhan main city are of highly vulnerability,and once they closure,they will have a serious negative impact on the efficiency of the urban road network.In addition,regression analysis results show that there is a significant correlation between road network vulnerability and land use and transportation factors.In terms of transportation elements,areas with dense road networks are more vulnerable,but the current imperfect subway line construction leads to uneven distribution of traffic demand and high vulnerability along the subway network;in terms of land use,layout of high-grade commercial facilities and high density areas of recreational facilities attract more traffic demand,areas near residential areas and public service facilities generate more traffic demand,and the vulnerability of the road network is relatively high;the vulnerability of the road network around industrial land is relatively low.At the same time,the vulnerability risk spatial identification results of superimposed real-time road conditions data show that the road network of the Hankou and Wuchang Central Group has high vulnerability and high risk characteristics,which needs to be control by long-term coordination of land use and transportation;the Wugang,Donghu,Luoyu,Guanshan,and Chaokou groups are high-risk spaces,and need to optimize land use and traffic layout while coping with reducing traffic congestion;the remaining groups are comprehensive groups and need to be comprehensively consider the countermeasures of transportation supply and demand balance.Based on multivariate big data and the perspective of traffic supply and demand,this paper conducts a road network vulnerability assessment and improvement study,which improves the current data distortion of the vulnerability assessment and the complexity of the model research,fills the gap in the quantitative research of the traffic demand perspective.The correlation between land use and transportation factors and the vulnerability of the road network enriches the methods and theoretical systems of vulnerability assessment as well,and provides a scientific reference for coordinating landuse and transportation layout,thereby balancing the distribution of transportation supply and demand,and ultimately improving the vulnerability of the road network.