This document is the master's thesis of Takashi Kataoka from February 7, 2006. It examines the effect of providing guidance information to reduce congestion in theme parks. The study builds a model where there is time delay in how users' facility selections are reflected in the guidance information. It finds that including the number of people moving to each facility in the guidance information helps distribute visitors more evenly among attractions. However, too much decentralization with guidance information may not be effective in overly crowded parks, and other synchronization avoidance methods may work better. The thesis has been published in 4 conference proceedings between 2005-2006.