Routes, buses and the children on them.

Each bus carries its registration, capacity, driver, attendant and the expiry dates of its insurance, fitness and pollution certificates. Papers about to lapse are surfaced on the fleet list a month before they do, because a bus with expired insurance is not a paperwork problem — it is a bus that must not leave.

A route is an ordered list of stops with pickup and drop times and an optional fare. Children are assigned to a stop, not to a bus, so changing the vehicle on a route does not require touching two hundred records. Capacity is enforced: a full bus refuses another child.

A driver starts the trip on a phone. Location sharing begins with the trip and ends with it — a bus that is not on a school run is not the school’s to follow. The driver marks each child on or absent at their stop, and the family is told either way.

If a bus is running but has stopped reporting, that is shown as its own state. A vehicle out with children aboard and no signal is the case worth catching, and hiding it inside “not running” would be the wrong answer.

Only their own child’s bus: its position, the next stop, a rough arrival estimate, and the driver’s name and phone number. When the bus is close to their stop they are told, once.