We are developing human activity simulations that could be used to test distributed video sensor networks. Our ultimate goals are to build statistical models of pedestrian density and flows at a number of urban locations and to correlate those flows with population movement and density models represented in a spatiotemporal modeling system. In order to create known populace flows, we have built a virtual populace simulation system, called CAROSA, which permits the authoring of functional crowds of people going about role-, context-, and schedule-dependent activities. The capabilities and authoring tools for these functional crowd simulations are described with the intention of readily creating ground truth data for distributed sensor system design and evaluation.