Depending on the layout of the school, a school bus should wait around 15-17 minutes at maximum to allow for everyone to board the bus, but not keep children waiting for too long.
I hope this helped.
The Driver should wait 10-20 minutes depending on how many kids there are, They should also have a list of the kids, if a kid doesn't enter the bus a teacher should be contacted. All though most schools wait 5 minutes then leave, usually don't come back to get kids.
