A Technology Based On Image Processing To Detect And Determine The Traffic Conflict At The Signalized Intersection

It is of great importance to the safety operation of the city for signalized intersection.As an important road node,intersection where a large number of various traffic participants cluster together,will result in being very prone to traffic conflicts and accidents.Most of the current research about signalized intersection is at level of qualitative safety assessment and analysis.For the lack of accident data,most of the research based on traffic conflict technology is broadly to safety analyze for safety question.The study of traffic conflicts is mostly the analysis of type and its mechanism.Determining whether the conflict occurs and calculating traffic conflict severity remains to be studied further.In response to these problems,this paper takes the conflict between the straight vehicle and left-turning vehicle at the signal intersection(straight-left conflict)as the research object.Firstly,through analyzing the theory of traffic conflict and the straight vehicle,left-turning vehicle,straight-left conflict traffic characteristics at the intersection,comparing various methods of discrimination,select the deceleration as a judge whether the conflict occurred.After the collision has been determined,the severity of the conflict is further divided by the deceleration.Aiming at the limitation of traditional conflict observation method,it is proposed to use video image processing technology to obtain the movement position of vehicle when collision occurs.In order to obtain the efficacious data of the indexes,a reasonable observation video method is carried out.And then,the vehicle trajectory information is extracted by the Tracker software in the straight left turning vehicle interaction of the surveyed video image.It is necessary to analyze the error to ensure the accuracy of the data.Divide the interaction of the movement,the obvious conflict,interference,no conflict.According to the theory of insertable gap,choose the method of WU,the critical of the deceleration is determined by passing the collision point as the acceptance gap to the left turning vehicle.After the conflict of all the data is judged,three levels is divided to the severity of conflict by the deceleration determination criteria.They are general conflict,medium conflict and serious conflict.by using the data fitting,the distribution of deceleration is obtained by data simulation.The validity of the conflict judgment using image processing technology is verified.It can automatically achieve traffic conflict identification by the image processing technology.On the basis of the result of conflict judgment,the actual significance of conflict judgment is further analyzed.