Which of the following best describes the relationship between OCS and yard limits?

The correct understanding of the relationship between OCS (Occupational Control System) and yard limits is that they can occur simultaneously. Both OCS and yard limits are crucial aspects of railroad operations, designed to regulate train movements and ensure safety in different contexts.

In situations where yard limits are established, they define a specific area within which a train may operate under rules that allow for different levels of authority, primarily focused on managing movements in a yard or similar setting. On the other hand, OCS is utilized for authorizing train movements in work zones or other designated areas, ensuring that track crews can safely work without interference from trains.

The simultaneous occurrence signifies that while yard limits dictate the rules for operations within a yard, OCS may still apply if there are maintenance activities or specific work being conducted within the vicinity of or adjacent to the yard limits. This overlapping function is critical for ensuring worker safety while maintaining train operations, indicating that both systems can coexist effectively, dependent on the operational context.

In contrast, the other options introduce hierarchies or conditions that do not accurately reflect the standard operational practices wherein both yard limits and OCS can be applied together without one necessarily overriding the other. Thus, the assertion that OCS and yard limits can occur simultaneously captures the