When a signal indicates restricted speed while departing a block system, when can maximum speed be resumed?

The correct answer reflects the specific guideline regarding the resumption of maximum speed when departing a block system under the conditions of restricted speed. After a signal indicates restricted speed, the rules state that maximum speed may only be resumed once the leading wheels of the train have cleared the opposing distant signal, or after traveling for a distance of two miles.

This is crucial because it ensures safety and proper adherence to operational protocols, especially in areas where trains could potentially encounter conflicting movements. The purpose of this rule is to minimize risk by requiring a cautious approach until the train is well-clear of potential hazards associated with opposing traffic.

The other options do not align with the established regulations governing speed resumption. For instance, resuming maximum speed "after one mile" does not account for the specific signal clearance requirement, while stating that a crew member can authorize the signal does not comply with signal indications that govern operational safety. Finally, fashioning the requirement to resume speed only upon entering a new block may overlook the necessary precautions needed within the previous operational limits. These factors underscore the importance of strictly following the prescribed conditions outlined in the GCOR.