In this research, we show a paradox of the “theme park” problem. In the crowded amusement park, it is generally believed that the equalization of queue lines of people can decrease the waiting time for riding on attraction. However, the equalization of queue lines occasionally increases the waiting time in the case where congestion degree is over the limit of capacity. This paradox makes it difficult to reduce congestion. In this paper, we propose a method to reduce the waiting time even in the “theme park paradox” situation, and evaluate effectiveness of our method by multiagent simulation.