What should you do before driving behind a coal loader?

The correct approach before driving behind a coal loader is to alert the operator. This action ensures that the operator is aware of your presence and can take necessary precautions to maintain safety while operating heavy machinery. Given that coal loaders are large and can have significant blind spots, communicating your intentions is critical. It helps prevent accidents that could occur due to miscommunication or the operator not being aware of a vehicle approaching from behind.

The other options do not prioritize safety effectively. Speeding up could lead to dangerous situations, as it may not give you enough time to react if the loader moves unexpectedly. Waiting for signals is a good practice in some scenarios; however, in the case of approaching a coal loader, the proactive step of alerting the operator is more relevant and immediate. Honking your horn might not convey clear communication, especially if the noise of the loader makes it difficult for the operator to hear. Therefore, alerting the operator stands out as the essential and correct action in this situation.