What does it mean if a school bus has its red lights flashing?

When a school bus has its red lights flashing, it indicates that the bus is loading or unloading children. This activation of the flashing red lights is a critical safety measure designed to alert other drivers that they must stop their vehicles to ensure the safety of children getting on or off the bus.

The flashing lights serve as a visual warning, signaling that children may be crossing the street or moving in proximity to the bus. Drivers are legally required to stop when they see these lights in order to prevent accidents and protect the lives of young students. This is particularly important in residential areas or near schools where children are likely to be present.

In contrast, the other options describe situations that do not involve the specific safety conditions requiring drivers to stop. For instance, if a bus were preparing to leave a stop, the lights would not necessarily be flashing, as the focus would be on ensuring that the children are safely on board before departing. Similarly, when a bus is operating normally or making a general stop without the intent to load or unload children, the red lights would not be engaged, thus not signaling the same urgency for other motorists.