I should have been clearer. It doesn't matter that the 9-year-old comes home on a bus vs walking. They still are not allowed to stay at home by themselves for

I should have been clearer. It doesn't matter that the 9-year-old comes home on a bus vs walking. They still are not allowed to stay at home by themselves for hours after school every day, even if they take the bus. It's not the conveyance, it's that the parent is no longer on the premises at all. I simply chose walking because most of the kids in our neighborhood walk to school.