Intersection traffic flow analysis and analysis of algorithms,design of algorithms,this paper,the vehicles unified identification as a standard car equivalent steps of the algorithm based on the decision-making on the flow of traffic junctions,the algorithm is applicable not only to single coil detector or single magnetic detector such as a single detector,but also applies to dual-loop detectors.The detection process is simple and can achieve very high accuracy rate,and through case studies,to verify the effectiveness and accuracy of change algorithm.