Atlas is an analysis and design program used for signal lights and signs supported by the dual cable system. The analysis consists of an iterative technique which is a combination of the Force Density Method (FDM) and the Direct Stiffness Method (DSM). The FDM is ideal for the analysis of cable structures whereas the DSM is the most widely used technique for the analysis of framed structures. The nature of the structures under consideration lead to the development of this analysis technique, which is a combination of the two methods. Atlas handles the wind loading in a realistic manner. It allows the user to specify the wind speed as well as the areas of the signal lights or signs (parallel to the X and Y axis). In so doing, the program calculates the applied loads on the corresponding nodal points internally, based on the specified element areas of the Light elements in each plane. The loads are calculated in each cycle of the nonlinear process. Therefore, the applied loads in each cycle change with the rotation angle of the light. Atlas is also in compliance with the latest FDOT Design Standard Index. Engineers can place multiple poles at locations of interest to design multiple-span signal systems, including the Box configuration.