Over the past decade the United States has endured many disasters, both man made and due to the forces of nature. In each case, leadership in the public and private sectors learn that more needs to be done to ensure continuity of life and economy. After a catastrophic event, the public sector leadership has to ensure that government is functioning and that affected communities are provided the proper support. Within the private sector, there is a need to ensure that the employees are cared for and that there is a continuity of the business. We have learned that while the specific needs of the public and private sectors after a catastrophic event are unique, there is an overriding need to prepare for the eventual disaster. Disaster preparation is of extreme importance in providing emergency assistance, allowing for evacuation, or ensuring the communications and public safety needs are met before, during, and after an emergency. For a large metropolitan city, the planning efforts take on many levels, due to the complexity of the groups have jurisdiction over the planning and relief efforts. Northern Illinois University and Argonne National Laboratory, working with the State of Illinois and the Chicago Metropolitan Agency for Planning (CMAP) partnered to study the effect of such a catastrophic event in the city of Chicago. In any disaster planning scenario, the planners must have the ability to predict how the people who live and work in the region will react to catastrophic events. This planning need to take into account the major and minor transportation routes as well as the public transportation modes, allowing individuals to exit the city. In addition, the planning must also be able to identify routes for emergency vehicles entering and exiting the city, as well as transportation of injured between hospitals. TRansportation ANalysis SIMulation System (TRANSIMS) traffic micro-simulation code, developed by the U.S. Department of transportation, was utilized to model the complex city and its transportation routes. TRANSIMS offers many capabilities that are needed when modeling emergency evacuation scenarios. The software system is capable of simulating individual travelers, their routes, and their transportation mode (such as traveling by car, public transit, or walking) and calculates traffic patterns on the basis of the microscopic interactions between individual vehicles and detailed street network features. This information was developed based upon complex surveys and satellite imaging. Through this software researchers were able to model events and transportation into and out of the city. In addition, undergraduate and graduate students were involved in this complex year-long project. The authors will provide information as to the modeling, input, and output that was obtained. Through an analysis of the motion of the population working and living in the city, planners have a much better Page 14.494.2 understanding of how to react to emergencies that might occur, and ensure that emergency relief can get to the...