A traffic control device that controls traffic of data transmitted from mobile units that belong to different groups, includes a distribution section that switches an output destination for the data in accordance with a group and a type of the data, a plurality of data storage sections that store the data output from the distribution section on a first-in-first-out basis, a timing adjustment section that adjusts an output timing for the data stored in the data storage sections in accordance with the group and the type of the data, and an identifier attachment section that attaches an identifier to the data output from the data storage sections in accordance with the group and the type of the data.