Research On The Traffic Congestion Situation Identification And The Relief Countermeasures Of Arterial Roads In Winter Cities

Winter cities are a special urban group distributed in the Northern hemisphere.Due to weather conditions,seasonal restrictions and other reasons,winter travel conditions in winter cities are generally poor.The construction of rail transit such as subway and light rail is slow,and the promotion of emerging public transportation methods such as rapid transit is relatively slow.Conventional bus is often the main body of public transportation.Therefore,ground traffic pressure is greater than that of non-cold cities,and traffic congestion is more serious and complex.In order to effectively solve the problem of traffic congestion in winter cities and improve the efficiency of traffic congestion management winter cities,this paper takes the arterial roads of winter cities as the research object and centers on the functional characteristics and congestion characteristics of the arterial roads,focuses on the study of congestion identification,cause analysis and relief measures,and proposes a set of methods that can diagnose the "symptom" of arterial roads congestion in winter cities,explore the "pathology"of arterial roads congestion in winter cities,analyze the "pathogeny" of arterial roads congestion in winter cities,as well as the "prescription" to control and improve the congestion problem of arterial roads in winter cities.It can provide method guidance and technical support for traffic commanders,planning managers,and organizational decision makers to "suit the medicine to the illness".Analyze the relationship between congestion state and congestion trend,define the traffic congestion situation,and perform a collaborative description of congestion state and trend.The influencing factors of traffic congestion on the arterial roads of winter cities are analyzed from two aspects:traffic demand and traffic supply under special weather conditions.Combining the Density-Based Spatial Clustering of Applications with Noise(DBSCAN)clustering algorithm and the congestion density distribution curve,it is determined that the congestion state of the arterial roads in winter cities can be divided into three levels:unblocked,slow and congested,and verified by spatial-temporal autocorrelation.Based on the Hierarchical Cluster Method(HCM),the congestion trend of the arterial roads in winter cities is divided into three types:aggravating,improving,and stable.On this basis,the temporal and spatial characteristics of traffic congestion on arterial roads in winter cities are explored.It is proposed to divide the arterial roads in winter cities into traffic congestion analysis units according to a certain length,direction and arterial and auxiliary roads.Weighted average filtering,Grubbs algorithm,approximate bisect method and other vehicle GPS data cleaning and correction methods are designed.A road network map with geometric attributes is constructed based on ArcGIS and AutoCAD,and the "Table Link" function is used to load static data,the offset correction,buffer analysis technology and exploratory data analysis technology are used to match the vehicle GPS data to the corresponding direction and arterial and auxiliary roads.By counting the number of positioning points in the unit,number of units and number of units without positioning points,the granularity of the analysis unit is determined to be 200m,and ArcGIS software is used to realize the segmentation of the analysis unit,and the arterial roads traffic operation analysis unit database is established.Introduce the physics term "potential energy" to the problem of traffic congestion,draw lessons from the principle that robots operate under the action of attraction and repulsion in artificial potential fields,the mechanism of traffic congestion is internalized into the driving and repelling effects of traffic travel demand and traffic environment on the driver's psychology.Selecting 10 traffic environment elements with potential to trigger traffic congestion,based on the potential energy zero point and the principle of potential energy superposition,a traffic congestion potential energy model for arterial roads in winter cities is established.Decision Alternative Ratia Evaluation System(DARE)subjective weighting method,the Criteria Importance Though Intercrieria Correlation(CRITIC)objective weighting method and the Entropy objective weighting method are combined by multiplicative synthesis method to determine the weight value of each element in the model.The congestion potential energy perception level of travelers with or without ice and snow conditions is investigated,and the impact of changes in traffic congestion potential energy on the psychological perception of travelers is explored,and the probability function and distribution function of the congestion potential energy perception level with or without ice and snow conditions are obtained,and the classification threshold of congestion potential energy level with or without ice and snow conditions is determined.Based on the traffic congestion analysis unit database and the congestion potential energy model,the feasibility and effectiveness of the proposed method are verified by comparing with the actual situation.Considering that the congestion caused by different reasons has different external expressive form in time and space,analogy with the four-step diagnosis method of"Observation,Auscultation and Olfaction,Inquiry",a method for identifying the causes of traffic congestion of arterial roads in winter cities is established,which takes the three stages of"Model determination,Source tracing,and Cause reasoning" as the core,providing support for reasonably arranging the time sequence of congestion control and improving the efficiency of congestion control.According to the temporal and spatial characteristics of congestion,the congestion is divided into regular congestion and occasional congestion,and the K-means Clustering Algorithm(K-means)is used to calculate the frequency range threshold of regular congestion,and the programming language is used to search the unit group of regular congestion.Based on the analysis of the law of congestion propagation,a judgment criterion for tracing the source of congestion based on congestion propagation timing and the magnitude of congestion potential energy is proposed.On this basis,using the Fault Tree deductive reasoning method,based on the causal logic relationship between the causes of congestion,the regular congestion and occasional congestion fault trees of arterial roads in winter cities are constructed,and the occurrence probability of each cause and its importance in the Fault Tree structure are determined by Experts Scoring Method and Cloud Model,so as to guide the reasoning and diagnosis of the causes of congestion.Based on the analysis of the characteristics of the congestion situation and the analysis of the causes of congestion,the arterial roads traffic congestion countermeasures in winter cities are proposed from three aspects:guiding demand,expanding supply,and optimizing potential tapping.In terms of guiding demand,it is proposed to pay attention to land layout planning,formulate a humanized motor vehicle purchase restriction policy,and appropriately restore freight traffic,staggered commuting,home office,and scheduled travel,etc.,to adjust the amount of motor vehicle travel.In terms of expanding supply,it is proposed to combine far and near,gradually and rationally use economic resources,promote the construction of rail transit,strengthen the construction of conventional public transportation heating environment,change the space function of non-motorized vehicle lanes according to the season,build a threedimensional road network,and adopt anti-freezing pavement materials and technologies,optimizing linear design in consideration of climatic characteristics,etc.to improve the level of road infrastructure construction and improve the level of traffic management.In terms of optimizing potential tapping,it puts forward countermeasures such as effective use of temperature,wind,sunshine and other weather factors to turn the weather shortcomings of winter cities into potential ones,seize the application of intelligent transportation,improve the capacity of congestion management,and promote the overall improvement with small units.