When can a control operator operate switches and signals for adjustment?

The correct response focuses on when it is safe to operate switches and signals without interfering with train movements. Operating switches and signals for adjustment should only occur when it is determined to be safe and will not disrupt any ongoing train operations. This emphasizes the importance of operational safety and the need for clear communication and awareness of train schedules.

If control operators were to manipulate switches and signals without ensuring that it wouldn't interfere with trains, it could lead to delays, accidents, or conflicts that could jeopardize the safety of operations. Therefore, priorities must be given to maintaining a safe environment for both train movement and signal adjustments.

Regarding other answer choices, scheduled maintenance times could be accompanied by pre-determined protocols to maintain safety, but they do not account for instances outside those times that may be safe for adjustments. The presence of a train in the vicinity does not necessarily mean it is unsafe to operate switches, but rather focuses on a specific moment rather than overall safety. Operating only on weekdays restricts flexibility and does not reflect operational needs outside of those days.