Accessibility is usually defined as the possibility to reach some activities from a given point and with a given transport system. With respect to the comparison of different project scenarios, an accessibility analysis could be used like a Decision Support System for planning a territorial system, allowing a comparative evaluation based on accessibility variations. In this paper a methodology is proposed for the estimation of a transport terminal influence area based on an accessibility analysis. Moreover, some accessibility indicators specific for freight transport terminal are presented trying to overcome the main limits of the indicators presented in literature.