What is the appropriate response if the train operator notices a discrepancy in the route set by the tower operator?

When a train operator notices a discrepancy in the route set by the tower operator, signaling with four short whistle blasts is the appropriate response. This action serves as a critical communication tool that alerts other crew members and nearby personnel of a potential issue, ensuring safety and clarity in the operation of the train. The specific sound pattern of four short blasts is universally recognized in rail operations as a warning signal, indicating a situation that requires immediate attention.

This response is essential as it ensures that everyone involved in the operation is aware of the discrepancy and can respond accordingly to prevent accidents or operational errors. Additionally, it promotes a culture of safety and vigilance among train operators and support staff.

In contrast, proceeding as instructed without addressing the discrepancy could lead to serious safety hazards, while calling for assistance would be a delayed response when immediate alert is needed. Ignoring the discrepancy is not an option, as it compromises the safety of the train operation and may result in severe consequences. Therefore, effectively communicating through the designated whistle signal is vital in this scenario.