Study On Multi-level Road Traffic Congestion Index Based On Big Data

With the improvement of the level of science and technology,the technology and means of traffic data collection have been rapidly improved.Traffic management departments,traffic travelers and other concerns about urban traffic congestion have all raised their attention to the problem of urban traffic congestion.According to this,the research institutions compete to carry out the research of traffic operation index,which can be used to evaluate the traffic congestion quantitatively.However,on the one hand,most of the existing research on traffic operation index is based on single-factor indicators,but not on the basis of multi-factor comprehensive evaluation.On the other hand,the intersections are directly integrated into the road segment during the research process.The influence of intersection on traffic condition of road network is not considered separately.In this context,this paper establishes the traffic operation index model based on multiple indexes from the angle of intersection and road section,which can be used to comprehensively evaluate the road traffic operation and can reflect whether the road network congestion is due to intersection congestion or road congestion.Then the corresponding measures are adopted to alleviate the current situation of congestionFirstly,on the basis of combing the research of traffic operation index model and algorithm at home and abroad,according to the actual situation and data acquisition,this paper determines the intersection traffic operation index based on directional characteristics in this article,and the traffic operation index model of road sections based on directional characteristics is selected.The traffic operation index,which includes the steering saturation,steering queue length,and vehicle delay in the lane group as the original evaluation index,is based on the directional characteristics of the intersection traffic operation index model.In the road traffic index model based on the direction characteristics,the speed of separated direction the single-lane traffic volume and time share of lanes in the sub-direction units are used as evaluation indicators.According to the specification and other documents,the evaluation grades of the selected traffic operation indicators are divided,and the membership functions and degrees of membership of each traffic operation index at intersections and road sections are determined.Secondly,the improved method of principal component analysis is used to convert the original evaluation index of each turn of intersection into the whole evaluation index of intersection On this basis,the CRITIC assignment method is used to determine the weight of the evaluation index after conversion,and then,the traffic operation index of intersection based on directional characteristic is obtained.The fuzzy comprehensive evaluation model is used to fuse the evaluation indexes of road sections,and the road traffic operation index based on directional characteristics is obtained.Finally,on the basis of determining the intersection traffic operation index and the traffic operation index of the road section,the weight of the node is determined by using the road node load theory,and the weight of the road section is determined by using the section cascading failure ratio theory.The index of traffic operation index and traffic operation index of intersections is weighted,which will eventually yield a multi-level road traffic performance index.Taking the Jiulongpo Torch Avenue area of Chongqing as an example,the index model and algorithm proposed in this paper are analyzed and calculated,and compared with the traffic index of Gaude.It is concluded that the trend of road evaluation in this paper is basically consistent with that of Gaude traffic index.However,compared with the previous traffic operation index,the paper studies the intersection and the road section separately,evaluates the traffic operation condition of the road,and determines whether the traffic congestion source is the intersection or the road section,and provides a basis for traffic managers to take targeted measures.