What should train operators always prepare for when approaching signals?

Train operators should always prepare to stop if required when approaching signals because signals are critical indicators of the operational status of the tracks ahead. Signals dictate the train's movement—indicating whether it should continue at its current speed, reduce speed, or come to a complete stop.

Being prepared to stop is a fundamental safety protocol, as there may be situations where the signal displays a stop indication, which is essential for preventing accidents. Additionally, approaching signals at the appropriate speed and being ready to halt ensures that operators can respond quickly to any changes in the signal or track conditions.

While increasing speed may be appropriate in specific circumstances, operators should primarily prioritize stopping as necessary. Switching tracks and communicating with other trains are also important duties but are contingent on specific signal indications. Therefore, being prepared to stop is the most vital preparedness measure when approaching any signal.