PATH Train Engineer Recertification Practice Exam

The whistle signal for running against traffic is one long, one short. This signal is used to ensure clear communication and alertness among train crew members and nearby personnel, particularly in situations where a train operates in the opposite direction to the expected flow of traffic. The long blast serves as a warning that the train is approaching from a direction that may not be anticipated, while the short blast reinforces the urgency of the warning. This safety measure is critical in maintaining safety within the rail environment, ensuring that everyone is aware of the unusual movement of the train.

In the context of the other choices, options like one short, one long or two short, one long communicate different scenarios, such as standard departures or signals for crew communication that do not specifically indicate running against traffic. The three long blasts are often reserved for emergency situations or indicating a stop, which does not apply to this specific context of counterflow operation. Thus, one long, one short is distinctly recognized as the proper signal for running against traffic.