What should be done with the parking brake when a school bus is parked and left unattended?

When a school bus is parked and left unattended, the parking brake should be set. This is crucial for safety, as the parking brake is designed to hold the vehicle stationary and prevent it from rolling away. Setting the parking brake ensures that even on an incline or in the presence of wind, the bus remains securely in position, thus protecting the bus from accidents and ensuring the safety of pedestrians and the environment around it.

Additionally, setting the parking brake is a standard operating procedure that reflects responsible vehicle operation. It is part of proper vehicle maintenance and operation practices that promote safety in the transportation of students. Neglecting to engage the parking brake, or only partially engaging it, increases the risk of a mishap, which is why it's essential to always ensure it is fully set whenever the bus is parked and unattended.