The Carnival of Ivrea takes place inside the historical center of the city, according to the guidelines used on several occasions during the days of the event; it consists of 9 days and involves different areas of the city. From the point of view of the number of people involved and of geometric complexity, the most interesting events are those that take place in the historic center during the days between the Carnival Saturday and the Fat Tuesday. Therefore, a numerical model was constructed for each of the areas involved. Each square is modeled with its real dimensions, as a place where users are present according to the project crowding, and is connected to a network of routes that must guarantee the flow of users at the end of the event and / or in case of sudden necessity. In addition, the signage used for the event was totally customized to meet the needs and peculiarities of the specific event, different from any other for the type of activities that took place during the days.