Why is subway signal equipment such as junction boxes kept padlocked?

The choice that states subway signal equipment, such as junction boxes, is kept padlocked primarily to prevent tampering by unauthorized personnel is accurate because security and operational integrity are critical in subway systems. Junction boxes contain essential components that manage the signaling and safety mechanisms of the subway, and unauthorized access could lead to malfunctions, compromised safety protocols, or even potential hazards for trains and passengers.

By padlocking these junction boxes, transit authorities can effectively control who has access to sensitive equipment, thereby reducing the risk of interference with vital signaling systems. Ensuring that only qualified and authorized personnel can access such equipment is crucial for maintaining the reliability and safety of transit operations.

Other options might reflect valid concerns, but the primary reason for the locked status of these junction boxes is to guard against unauthorized tampering, which could have far-reaching consequences for public safety and transit reliability.