In which situation must a bus operator use hazard lights?

Using hazard lights is essential when the bus is stopped in an emergency or when loading and unloading passengers in a hazardous area because it serves to alert other drivers and pedestrians of the potential danger. This warning helps to increase visibility and indicates that the bus is stationary in a situation that could pose risks to safety. It is critical for preventing accidents, especially in environments where there may not be clear signage or space for a bus to safely stop.

In contrast, making a scheduled stop or entering/exiting a bus terminal does not necessarily pose an immediate hazard to other road users, and therefore, hazard lights are typically not needed in those scenarios. Additionally, traveling at high speeds does not pertain to the appropriate use of hazard lights, as they are meant to signify a stopped condition rather than an operational state of the vehicle.