Even when lacking an accurate association between the trajectory and identification of a moving body, the association between trajectory and identification of the moving body is estimated and the ambiguity quantified. An identification information association unit associates an individual trajectory link included in a trajectory link candidate with likely moving body identification information per trajectory link candidate. An association trend quantification unit quantifies a trend of the number of times when trajectory information is associated with moving body identification information per individual moving body identification information for individual trajectory information based on an association result between a trajectory link and moving body identification information. An association score calculation unit calculates an association score indicating ambiguity of an association between a trajectory indicated by trajectory information and a trajectory of a moving body identified by moving body identification information for each item of moving body identification information per trajectory information.