Abstract—Locations that connect tracks from different railroad companies - referred to as interchange points - exchange crew, locomotives, and their associated consists. Because trains have a single degree of freedom in movement, that is, they can only operate along the tracks, any delay occurring at an interchange point causes cascading delays in connecting tracks. In addition, authentication and authorization that is expected to take place at interchanges in PTC controlled train movement may add extra delays due to mutual authentication between two security domains. In this paper we propose a model that can address safety and security concerns and their interrelationships that govern train movement through an interchange point. We show how a profile of safe operations can be computed for operating an interchange point.