When can a track bulletin be issued to change a general order or special instruction?

A track bulletin is a critical form of communication within railroad operations that is used to convey changes or updates regarding general orders or special instructions. The correct answer emphasizes the necessity of proper authorization when issuing a track bulletin.

Specifically, a designated manager is responsible for ensuring that any changes to operating procedures or instructions are communicated effectively and adhere to the established safety protocols. This requirement helps to maintain consistency, safety, and reliability in railroad operations, as the authority to change such directives is not something that can be taken lightly or handled arbitrarily by just any crew member.

In contrast, other options do not encompass the necessary procedure for issuing a track bulletin. For instance, allowing a conductor to issue a bulletin at their discretion could lead to inconsistencies and potential safety risks. Similarly, issuing a bulletin only after a train arrives or restricting it to once per month would not address the immediate need for updated information that may arise in rapidly changing operational scenarios. Hence, the requirement for manager authorization ensures that all changes are coordinated and comply with organizational guidelines.