When entering DCS territory at a hand-thrown switch, where may the Form D line 2 authority be addressed?

When entering DCS (Distributed Centralized Traffic Control) territory at a hand-thrown switch, addressing the Form D line 2 authority at the location of the switch is the correct practice because it ensures that the authority is granted and acknowledged precisely where the operational transition occurs. This provides clarity to the crew about their authority and its parameters right at the switch, where they are likely engaging with the controls or oversight necessary for safe operations in that area.

Addressing authority at the location of the switch reduces the risk of miscommunication or misunderstanding about the limits of authority, as events may change rapidly in a rail environment. It allows the crew to directly link their authority to the specific geographical and operational context of their situation, facilitating safer and more effective train movements within the DCS territory. Other options might lead to potential confusion regarding the authority's scope and responsibility, as they relate to locations that may not be as relevant to the specific action occurring at the switch.