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In this study, we have proposed a mathematical Programming model for the tactical planning of freight railways, which addresses the train Formation Problem. This problem results in a multi-commodity network flow formulation that contains both integer and continuous variables. The modular structure of the statement allows consider the special conditions of the network under study and to testing various operating policies.
In this paper, the model developing process is described using a simple hypothetical network. Finally the results are represented and interpreted. Some of the model outputs are the economic train size, high priorily costs, and the formation plan for the freight trains.