The stop arm extends. The lights flash. The bus rolls to a halt. The children disembark.
But then something goes wrong.
A driver in the other lane doesn't stop. Or one behind the bus gets impatient and tries to pass.
Sometimes it ends in tragedy, as it did in a 2018 crash in Rochester, Indiana, in which a driver struck three children from the same family at a bus stop. A 9-year-old girl and her brothers, 6-year-old twins, were killed and a fourth child, 11, was seriously injured.
Horrific crashes like that are why states have a long history of hefty penalties for people who illegally pass school buses. Now, technology in nearly 2 dozen states and 40,000 buses is helping identify and punish violators.
