Although many traffic prediction models have been studied, much of the existing research considers traffic congestion primarily caused by construction and incidents. An effort to assess the impact of special events (ballgames, parades, conventions, etc.) in an urban area is needed. In this paper, a prototype model for traffic analysis under special events is proposed and tested. Unlike hydrodynamic modeling or the conventional microscopic approach by vehicle tracking, this model tries to decompose the overall system impact into the spatial effect of the special event network (SE network) and the temporal effect of the event-generated traffic. The model formulation is shown to possess a unique, physically meaningful solution to the underlying engineering problem. Using systemwide field data for model calibration, preliminary tests have shown encouraging results in predicting traffic impact on SE networks. Although further testing and improvement is needed, the proposed modeling approach has demonstrated its potential for extending to other applications such as disaster evacuation planning.