What is the primary reason for stopping behind a school bus with its stop sign activated?

Stopping behind a school bus with its stop sign activated is primarily about ensuring the safety of children. When the stop sign is extended, it indicates that children may be getting on or off the bus, and it is essential for drivers to halt their vehicles to create a safe environment for these children to cross the road. This action helps prevent accidents and ensures that children can safely navigate the area around the bus without the risk of being hit by moving vehicles.

Other considerations, while potentially relevant, do not capture the primary intent of this law. For instance, while avoiding a fine is a possible result of compliance, the heart of the law is rooted in the protection of children. Stopping to take a break or to alert other drivers does not address the immediate concern of pedestrian safety around the school bus during loading and unloading times. Thus, prioritizing the safety of children is the key reason for this requirement.