When approaching an interlocking with signals displaying different aspects, what should be a train crew's priority?

When approaching an interlocking with signals displaying different aspects, a train crew's priority should indeed be to anticipate a change in signal aspects. This understanding is crucial because signals can indicate various conditions such as track occupancy or the status of switches and crossings. By anticipating changes, the crew can better prepare for potential adjustments to their speed or actions in response to upcoming signals. This proactive mindset allows crew members to react promptly, ensuring the safety of the train and its passengers.

The other choices do not sufficiently emphasize the proactive nature required in dealing with signal aspects. For instance, maintaining speed without assessing the signal could lead to dangerous situations if a signal change occurs. Stopping for all signals, while seemingly safe, could disrupt traffic flow, particularly if the signals are indicating that it is safe to proceed. Approaching with caution is important, but it falls short of the strategic anticipation that keeps train operations safe and efficient. Hence, anticipating changes enables a more effective response, aligning with operational protocols and safety standards.