What does the abbreviation XO signify in railroad operations?

The abbreviation XO in railroad operations signifies a crossover. A crossover refers to a track arrangement that allows trains to move from one track to another. This is essential for routing trains in various directions, allowing for flexibility in train operations and movements, particularly in yard and terminal settings. Understanding the functionality of a crossover is crucial for maintaining safe and efficient train operations, as it impacts how trains navigate from one route to another, especially in busy areas.

In contrast, while terms like "cross over option" or "operator exchange" might suggest some operational aspects, they do not accurately represent the specific term used in railroad terminology. "Overhead clearance," though relevant to track safety and infrastructure, does not relate to the concept of XO and is not the correct interpretation of this abbreviation in the context of railroad operations.