| Urban road traffic accidents mostly occur at signalized intersections in space and mostly occur during signal conversion,which is green-to-yellow,yellow-to-red and red-to-green period.This paper studies on pedestrians and non-motor violation,crossing speed,gap acceptance behavior during signal conversion to put forward the pertinent safety promotion measures.To figure out these problems,1544 valid samples are extracted from 3 typical signalized two-phases intersections of in Beijing.The main work and achievements are as follows:(1)In the analysis of the characteristics of violation crossing in different crossing periods,the violations are subdivided into yellow light and all-red period violations,common violations during the red light steady period,and early start violations during the last 5s of the red light.To divide the violation sample into three categories,establishing a Logistic regression model which include three types of factors individual factors,situational conditions,and environmental conditions.The conclusion shows that whether or not there is a conflicting vehicle before crossing have a significant impact on the yellow light and all-red period violations;gender,stopping vertical position,waiting time,average traffic volume,and whether or not there is a conflicting vehicle before crossing have a significant ant effect on common violations;Transportation and the number of violations during the waiting time have a significant impact on early start violations.(2)In the modeling and analyis of the characteristics of crossing speed in different crossing types,Lasso regression is used to construct a speed model to analyze the significant influencing factors of different periods of traveling under three traffic modes,which effectively solves the problem of collinearity among influencing factors.The results show that the significant influencing factors of pedestrian and bicycle riders’yellow light and all-red period violations are the arrival distance,the start time of red light,the number of non-motorized vehicles in waiting process and the type of crossing path In common violations during the red light steady period and early start violations,the significant influencing factors are the type of crossing path,the type of routes before and after crossing,and the type of vertical crossing path,longitudinal position and waiting time.As for electric bike riders,during yellow light and all-red period and red light steady period,the significant influencing factors are conflict traffic volume,type of crossing path and number of non-motorized vehicles in waiting process;in early start violation,proximal speed is related to whether there are conflicting vehicles before crossing,and distant speed is related to conflict traffic volume.(3)In gap acceptance analysis of different periods,Relief algorithm is used to select features and bring them into binomial logistic regression and SVM model Comparing the differences of gap acceptance behavior between different periods of crossing by establishing gap acceptance model.The results show that the significant influencing factors of gap acceptance in yellow light and all-red period are the change of speed before crossing and the type of conflict vehicle;the factors affecting gap acceptance of common violations during the red light steady period are the crossing stage and clearance value;the factors affecting gap acceptance of early start violation are the gap value and the number of violation non-motor vehicles during crossing.Under the three periods of violations,the accuracy of the SVM gap acceptance models can reach 92%,which is significantly higher than that of the Logistic model. |
