When is a Track Authority considered to be in effect?

• A. When the "OK" time is shown on it.
• B. After the RTC approves it verbally.
• C. Only at the start of a shift.
• D. When the train passes the crossing.

Answer: (A)

Track Authority becomes effective at the exact time shown as OK on the document. That OK time is the trigger that makes the authority active, ensuring everyone knows precisely when the tracked movement is permitted. Verbal approval after the RTC may confirm status in conversation, but it does not by itself make the authority in effect—the written OK time does. It isn’t tied to the start of a shift or to the train simply passing a crossing; both events do not establish authorization. Once the OK time is reached, the movement is permitted under the authority until its end time or cancellation, provided all other conditions are met.