Conflict Features and Impact Factors of Severity in Weaving Area of Cloverleaf Interchange
To examine the conflict features and the key impact factors of conflict severity in the weaving area of the cloverleaf interchange of the urban expressway,this paper uses the North Ring Interchange of Chongqing city as the research object,and collected vehicles natural driving videos by UAV(Unmanned Aerial Vehicle).A vehicle target detection and tracking framework based on the YOLOX and Deep-SORT was established,and a total of 10483 vehicle trajectory data were obtained from aerial video.The longitudinal and lateral conflicts were extracted based on the relative positions of the interacting vehicles.The conflict events were categorized as minor,general and severe based on the two-dimensional expansion of the collision time metrics.The assessment of indicators of the multivariate Logistic regression model,Random Forest model and CatBoost model were calculated in consideration of the factors of macro 17 explanatory variables including traffic flow parameters and vehicle micro-motion parameters.The models with better performance for longitudinal and lateral conflict identification were selected,and the key factors affecting the severity of conflicts within the weaving area were further analyzed.The results indicate that lateral conflict is the main type of conflict in the cloverleaf interchange weaving area,and the duration of conflict is longer and the risk of collision is higher than that of longitudinal conflict.The general conflict has the widest distribution in the intersection area,followed by serious conflict,and minor conflict has the most concentrated distribution,which is mainly distributed in the vicinity of merging triangles.There are some differences in the degree of influence of different explanatory variables on the severity of the conflict,longitudinal serious conflict is significantly related to six indicators such as relative speed difference and target vehicle length.For the lateral conflict,the top five variables in terms of importance are the relative speed difference,the average headway spacing,the target vehicle speed,and the target vehicle transverse longitudinal position.The risk of collision increases dramatically when the relative speed is more than 20 km·h-1,the speed of vehicle is more than 60 km·h-1,and the average headway spacing is below 12 meters.
traffic engineeringconflict severityexpanded time-to-collisioncloverleaf interchangevehicle trajectory data
万方数据
维普
