When can a driver resume normal track speed after passing an advisory speed sign?

The correct choice is that a driver can resume normal track speed when they see a full clear indication from the signal. This guidance is grounded in ensuring safety and compliance with the control of train movements. Advisory speed signs indicate that the train must reduce speed under certain conditions, often due to track curvature, conditions, or other operational factors.

Once a driver passes this advisory speed sign, it is crucial for them to confirm that the following signal shows a full clear indication before they increase their speed to normal. This ensures they are operating under safe conditions and are clear of any potential hazards ahead.

Resuming normal speed without a full clear signal could lead to dangerous situations if there are unforeseen circumstances on the track ahead. The signal reinforces a system of checks that help maintain safe rail operations, ensuring that the driver has all necessary information before increasing speed.