The Route Availability Planning Tool (RAPT) operational prototype was deployed to Chicago in the summer of 2010, the first RAPT deployment outside of the New York departure airspace for which it was originally developed. The goal of the deployment was to evaluate the adaptability of RAPT's airspace definition, departure management and weather impact models to different terminal areas throughout the National Airspace System (NAS). This report presents the results of a summer-long evaluation of the Chicago RAPT operational prototype, in which the performance of RAPT algorithms and the effectiveness of the RAPT Concept of Operations were assessed. The evaluation included observations made by researchers simultaneously stationed at O'Hare terminal (ORD), the Chicago TRACON (C90), and the Chicago Air Route Traffic Control Center (ZAU) during several days of convective weather impact and post-event analysis of air traffic data from the Enhanced Traffic Management System (ETMS) and RAPT weather impact predictions and departure management guidance. The study found that significant departure delay reduction could be achieved through the use of RAPT in Chicago, and that RAPT effectiveness in "typical" corner post airspaces like Chicago could be further increased with some modifications to the Concept of Operations, user training, and site adaptation.