The holding of urban large-scale activities usually brings heavy pressure on the operation of the transportation system. It is necessary to analyze and evaluate the traffic impact of venues and surrounding areas. The research can provide a scientific theoretical basis for traffic management departments to formulate relevant traffic control schemes, organizational optimization schemes, and operation scheduling schemes. The research constructs an evaluation index system from three dimensions: time, space and degree of the impact of large-scale activities on traffic operation in the surrounding areas of venues. The index values are calculated based on bus IC card data, subway AFC data, urban road detector data, taxi meter data and GPS data. Then, the research uses the method of maximizing deviation to assign a weight to the evaluation index and obtains the traffic impact index of urban large-scale activities by weighting calculation. Finally, the research uses the K-means clustering method to grade the traffic impact the degree of urban large-scale activities. The research takes the large-scale activities held in Beijing workers' stadium in recent years as an example to verify. The results show that the traffic impact evaluation method proposed in the article has good applicability and can clearly distinguish the impact degree of different large-scale activities on traffic operation. Keywords: large-scale activities; impact evaluation; traffic impact index

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