If you want to know why there are 3 black lines on the side of the iconic yellow school buses, ClawBoss, a school bus driver explained the meaning of the distinct black lines that are located on the side of yellow-orange school buses in the United States. Typically, these rails are for the safety and security of the bus and its inhabitants.
Not only do these add structure to the side of the bus so if the bus gets hit it’s stronger but in the event of an accident they actually give firefighters an idea of where to cut.