What is a key indicator for transitioning from MATC mode?

The Train Operational Display signals serve as a key indicator for transitioning from MATC (Motorized Automatic Train Control) mode because these signals provide critical information regarding the current operational status of the train. The display often includes vital data such as speed, position, and control commands that are essential for safe and efficient train operation.

In a MATC context, these signals help the operator determine when to switch to a different operational mode, particularly when safety and performance parameters require it. For example, if the display indicates that the train has reached a specific location or is approaching a critical speed limit, the operator can assess whether it is safe to transition to another mode. This process is essential for maintaining safety standards and ensuring the smooth operation of train services.

The other options, while relevant in various contexts, do not serve as direct indicators for transitioning from MATC mode. A passenger's safety briefing relates to ensuring passenger awareness and safety but does not influence operational mode changes. The train's speedometer reading is important for monitoring speed but does not encompass broader operational signals necessary for transitioning modes. Communication from the yard master is vital for operational coordination but is not a direct indicator like the Train Operational Display signals are.