When must a school bus have its stop sign activated?

A school bus must have its stop sign activated when children are entering or exiting the bus. This is a crucial safety measure designed to protect students as they board or disembark from the bus. The activation of the stop sign and the flashing red lights serves as a warning to other drivers, indicating that they must stop and not attempt to pass the bus. This precaution is particularly important during busy times when children may be crossing the street or moving around the bus. Ensuring that the stop sign is activated helps to create a safe environment for all students involved, minimizing the risk of accidents and promoting their safety as they travel to and from school.