When must you not pass a school bus?

When a school bus has its red lights flashing, it indicates that the bus is either loading or unloading children. This is a critical safety measure to protect children who may be crossing the street or waiting to board or disembark. Passing a school bus in this situation is illegal and dangerous, as children may be unpredictable and can suddenly enter the roadway.

The law is designed to ensure that drivers remain vigilant and stop their vehicles to provide a safe environment for students. In contrast, the other options do not present situations where passing a school bus is prohibited or could endanger children. For example, if the bus is not in motion or if it is during non-school hours, different rules apply.