(AP) — A suburban Omaha school district has installed devices on its school buses that allow officials to track not only the vehicles, but the students on it.

Gretna Public Schools has given students electronic cards to wave in front of a card reader each time they get on and off the school bus.

The system allows the district to track who is on which bus and when and where they board and get off.

The buses are also equipped with GPS devices. If there’s an accident or bus breakdown, the district knows where the bus is and who’s on board. If a child gets off at the wrong stop, officials can alert the parents. Officials can even determine whether buses stop at railroad crossings