What must a driver do if they see a school bus in their rearview mirror with flashing lights?

When a driver sees a school bus in their rearview mirror with its flashing lights activated, the appropriate action is to stop their vehicle. The flashing lights indicate that the bus is either stopping to load or unload children, or that it has stopped and children may be crossing the road. Stopping ensures the safety of the children, who might be getting on or off the bus, and is required by law in most jurisdictions.

Drivers are expected to wait until the flashing lights are turned off and the stop arm, if extended, is retracted before proceeding. This law is in place to protect children, as they are often in vulnerable positions when entering or exiting a school bus. Moving forward, speeding up, or changing lanes could create dangerous situations and potentially lead to accidents as children may be crossing the street at that moment. Honking the horn is not an appropriate response, as it could startle children and increase the risk of harm.