Congested traffic shows very complicated and stochastic features. One of the most interesting features is the amplification/decay of perturbations, indicating the development of small speed oscillation in the downstream into the large speed oscillation in the upstream. While traffic theories attempt to explain this phenomenon, the mechanism of the speed oscillation is not yet clear in the aspect of drivers’ behavior. Similar phenomenon is also found in a long waiting line such as in front of the stadium or theater ticket box. In this paper, the stop-and-go movement in the waiting line, which is relatively easy to understand than the vehicular movement, is modeled and simulated. From the simulation, it is found that the amplification/decay of perturbation exists in the waiting line and shows similar pattern as in the vehicular movement.