Research On The Impact Of Accessibility On Traffic Status For Urban Road Network

Traffic congestion has been taken more seriously than ever before,and it is becoming more important to improve the efficiency of the use of existing road network while it has been proved building new traffic facilities isn't the best way to solve the problem.Among many indicators to evaluate the efficiency of road network,accessibility is a comprehensive index,which reflects the convenience of road network contact,and plays an important role in the overall performance evaluation of urban road network.Research and applications about accessibility at home and abroad has been rich,but lack of road network accessibility and the study of the quantitative relationship between traffic congestion.Based on this,this paper studies the accessibility index of urban road network,analyzes the interaction between accessibility and traffic status to improve the efficiency of road network operation,and alleviates the problem of urban traffic congestion.This paper summarized the existing study results about definitions,influencing factors and evaluation models of accessibility,and then selected the appropriate parameters to establish the calculation model of urban network accessibility based on travel time to analyze the impact of accessibility to traffic condition.Considering the accessibility of network with different size and form is difficult to compare,and the connection and structure of the road network directly affecting accessibility,this paper put forward a concept of relative accessibility,which can reasonably evaluate the accessibility of different networks.In order to study the traffic status of urban road network,this paper defined the connotation of traffic evaluation and determined the key influence parameters of traffic condition,and defined the traffic state index—congestion degree which is from the state of intersection and section to analyze network state.According to the relationship among traffic state,level of service and degree of saturation,this paper determined the critical value of the crowded degree under different traffic state,and analyzed the applicability of the model.Finally,taking the road network of Xi'an High-tech Zone as an example,this paper evaluated the state of road network from the aspects of accessibility and connectivity,and analyzed the stability of road network traffic status;the status quo of road network nodes in the quantitative relationship between accessibility and crowded degree was studied,and got certain quantitative relation,and then through a variety of solutions to further confirmed that there is a negative correlation relationship between the two;this paper analyzed the change of accessibility and network state before and after the implementation of the new scheme to verify that the new schemes can improve the efficiency of road network operation.And results of this paper can provide some reference for traffic managers to take measures to alleviate urban traffic congestion.