Which of the following best describes interlocking?

Interlocking refers to a safety system used in railway operations that prevents accidents by controlling the signals and switches to ensure that conflicting movements of trains cannot occur simultaneously. This involves a series of interconnected mechanical or electronic devices that coordinate the movement of trains across junctions and crossings. By ensuring that signals are positioned according to the track switches and that the position of the switches is safe for train movement, interlocking systems play a crucial role in maintaining a safe operating environment for trains.

The primary purpose of interlocking is to eliminate the possibility of trains being directed onto a track occupied by another train, thereby enhancing safety. It integrates various components like signals, track switches, and even communication systems to provide a comprehensive method of safeguarding rail traffic.

The other options do not accurately capture the essence of interlocking. A system for coordinating track maintenance relates more to scheduling and logistics rather than safety signals. Managing train schedules pertains to planning the timing and routing of trains rather than directly preventing accidents. While procedures for track switching might be part of the overall operation, they don't encapsulate the comprehensive safety aspects that interlocking systems are designed to address.