When will the cab signal indicator not indicate the conditions ahead?

The cab signal indicator is designed to provide information about the conditions ahead to the engineer, helping to maintain safe operations. However, there are specific circumstances under which this indicator will not accurately reflect the conditions in front of the train.

When an engine is pushing cars, the cab signal indicators may not provide reliable information. This is because the signals are primarily designed to be utilized when the locomotive is pulling trains. In the pushing scenario, the train is not inherently designed to have the same level of cab signal functionality, leading to the possibility of misinterpretation of signals or, in some cases, total lack of indication of signal aspects ahead.

Other scenarios like operating normally, approaching a station, or pulling freight do not inherently disrupt the operation of the cab signal system. Thus, those conditions would be expected to display the appropriate signals as required. In contrast, pushing cars introduces complexities that can affect the indicator's reliability.