Why does the Zum app show my child’s bus departing school after dismissal but does not display as delayed?

Afternoon bus routes do not begin as soon as soon as schools dismiss. Buses normally depart schools within seven minutes of the end of the school day to allow time for students to exit the building and board the buses. For example, if an elementary school day ends at 3:55 p.m., the bus is not expected to begin its route until 4:02 p.m., which is considered an on-time departure for that bus.