This Master thesis presents the utilization in transport modeling the new paradigm in software development, the Object Oriented Program (OOP). The using of OOP seeks improve the flexibility, productivity and efficiency in software developed under such principles. This will be done thought its characteristics: inheritance, polymorphism and encapsulation. The application of the OOP principles has been done adjusting the software TRAFFIC, developed in the University of Montreal. The model will be used like a decision making tool for the urban network transportation planning, ai a strategic level. The software assigns vehicle flows on road networks in order to minimize the user cost, following the first Wardrop`s principle. This research has been based on the Fusion method, that presents a systematic approach for development of object oriented software. The method also is directed toward the requirements of development with and for reutilization. The study will be developed at the level of analysis, project and implementation.