What is indicated by Line 3 authorization on a Form D?

Line 3 authorization on a Form D is specifically associated with granting permission to operate safely past stop signals. This type of authorization is critical in ensuring that trains can proceed when necessary, despite the presence of physical signals indicating to stop. It is particularly important for maintaining the flow of rail operations, allowing for planned movements that might otherwise be impeded by signal indications.

In the context of rail operations, passing a stop signal under Line 3 authorization typically comes with specific conditions or restrictions that must be adhered to for safety reasons. This ensures that train dispatchers can manage traffic effectively while maintaining safety protocols necessary to prevent accidents or conflicts on the tracks.

Understanding the context of the other options clarifies further why this is the correct selection: permission to travel at maximum speed would not be appropriate in this scenario, as passing a stop signal generally involves caution and reduced speeds. Granting full control over the interlocking refers to different operational controls and might not relate directly to the act of passing a stop signal. The requirement for track inspections, while critical in a comprehensive safety framework, does not connect to the specific authority indicated by Line 3 on a Form D.