What is the main purpose of the hand-held stop sign used by bus drivers?

The main purpose of the hand-held stop sign used by bus drivers is to signal traffic to stop. When a school bus has its stop sign extended, it indicates that children are boarding or disembarking from the bus, and vehicles must stop in both directions (unless on a divided highway) to ensure the safety of the students. This visual signal plays a crucial role in preventing accidents and protecting children as they enter or exit the bus.

This is a critical safety measure, as the stop sign serves as a clear, universally understood indication that vehicles should not proceed until the bus has retracted its sign and children are out of the way. Understanding this function is vital for drivers to ensure they comply with the law and contribute to the safety of children during school transportation.