When is it acceptable for a school bus driver to use the horn?

The correct answer is centered around the idea of maintaining safety in a school bus driver's operations. Using the horn is primarily intended for ensuring safe operation, which can encompass a range of situations where the driver needs to communicate their presence to other road users or alert them to potential dangers.

For example, a driver might use the horn to alert another vehicle that is encroaching into the bus's pathway, thereby preventing a potential accident. This aligns with the overarching goal of all school bus operational practices, which is to keep students, the driver, and other road users safe. So, the clarity in using the horn contributes directly to the safety measures necessary in managing a school bus effectively.

In contrast, signaling other drivers or alerting pedestrians, while important, does not encapsulate the broader responsibility that a driver has in actively ensuring safety. Using the horn solely in emergencies could limit the driver’s ability to prevent those emergencies from occurring in the first place. Therefore, focusing on the broader aspect of ensuring safe operation aligns with the best practices for bus drivers.