Why do school buses have crossing arms?

School buses are equipped with crossing arms to enhance the safety of children as they board and disembark. The crossing arm extends out from the front of the bus, creating a visual barrier that signals to drivers to stop and not pass the bus while children are crossing the street. This helps prevent accidents and ensures that children have a clear and safe path to and from the bus. Overall, the crossing arm is a critical safety feature aimed at protecting young pedestrians.