What is the primary function of a switch in a railway yard?

The primary function of a switch in a railway yard is to redirect train cars from one track to another. Switches, also known as points or turnouts, are integral components of railway infrastructure that allow for flexible routing of trains and train cars. By adjusting the position of the switch, railway operators can guide rolling stock toward different tracks, facilitating efficient movement within the yard.

This capability is essential for managing train traffic, coordinating loading and unloading operations, and ensuring that trains can be combined or divided as needed. Such maneuvers are crucial in busy railway yards where multiple trains need to interact and share tracks.

While connecting different railway lines or signaling train movements are also important functions in a railway system, they do not directly pertain to the specific, primary role of a switch. Additionally, switches do not maintain speed; their primary purpose revolves around directing the flow of rail traffic. Therefore, the option highlighting the ability to redirect train cars accurately captures the essence of a switch's role in a railway yard.