Study On Vehicle Lane-changing Collision Risk On The Approach Of Intersection Based On Video Data

The intersection is widely recognized as the bottleneck of the road network,the traffic environment near the approach of the intersections is complex and changeable.Due to lots' of factors,there is lane-changing demand for vehicles which could cause traffic conflict and crash.In many countries,huge amounts of money have been spent on crash at intersections,but that seems not successful.Therefore,this study analyzed the risk factors and the risk of micro-conficts for lane-changing vehicles on the approach of intersection,which could provide theoretical reference for road risk analysis and guidance for traffic safety improvement.Contents and findings are in the three followings.This study began with the statistical analysis of crashes at intersections in the city of Wisconsin.By using the data,three different regression models were constructed in the view of road environment,and after comparison and cross-validation between the three models,the results showed the Adaptive Lasso regression model had higher accuracy than the Logistic regression model and the Lasso regression model.According to parameter estimates,the influence between risk factors and fatal & injury crashes which caused by vehicles lane-changing was qualitatively analyzed.Secondly,the type of lane-changing and the process of conflict were expounded,and lane-changing conflict process was also described.The relationship between the collision and conflict was analyzed,and three types of risk were also introduced.As many limitations of safety evaluation based on collision statistics,typical intersection-related parameters were counted through video surveys.What's more,the risk of vehicle forced lane-changing and squeeze lane-changing was analyzed in the view of the microscopic level.For the forced lane-changing,two types were categorized by lane-changing vehicle movement status.When the vehicle moves at a constant speed,a minimum safety distance model was constructed,and the recommended limits for video survey intersections were given from the perspective of lane-changing safety distance.When the vehicle decelerated,the relationship between Time-to-Collision(TTC)and the deceleration of the lane-changing vehicle was counted.According to TTC,conflict risk was divided into five types including safe,safer,general danger,more danger and serious danger.For the forced lane-changing,combining with vehicle dynamics,it is taken into account that the occurrence of collision depends on the braking condition of the target adjacent lane vehicle.By analying the distribution of maximum deceleration and vehicle spacing between the target adjacent lane vehicle and the lane-changing vehicle,the squeeze lane-changing conflict risk was also divided into five types including safe,safer,general danger,more danger and serious danger.Finally,the improvement strategies were proposed based on the analysis of lane-changing collision and conflict risk factors.Maintenance of lanes and distances based on active intervention was proposed,including a method for designing a colored road surface for intersections with corners,and a driver visibility distance model based on active intervention for variable lane intersections.What's more,traffic conflict improvement ideas at the traditional intersections and traffic design at the new intersections were introduced.