Why is backing a school bus discouraged, and what must the driver do if backing is unavoidable?

Backing a school bus is strongly discouraged because the area directly behind the bus is a large blind spot where a child could be standing unseen. Routes are planned to avoid the need to back whenever possible. If backing truly cannot be avoided, the driver should use a posted lookout — such as an aide or responsible adult — to watch the rear, sound the horn to warn anyone nearby, check all mirrors continuously, and back very slowly, stopping immediately if there is any doubt. The safest practice is to plan turnarounds that eliminate backing where students may be present.