When DS was in elem., we had a plan in place, but it would not work for most. Our school is 1.6 miles from home. The bus takes a direct route (although there are stops in between). But that means that the furthest the bus is from either school or home is .8 miles. The plan was in case of emergency bus either turns around and heads back to school, radioing nurse on the way so she is waiting, or if close to our home, skip all stops in between and head straight to our house. Which could have been a problem if I wasn't home, which sometimes I wasn't, but usually was. Obviously, reverse that for morning.
The bus did, one time, pull out of the parking lot, turn around, and pull right back in. DS was having a seizure (epilepsy was the other reason for this plan). Of course, this was the day I was out in the yard waiting for the bus, with the phone inside. So the bus was quite late, then DS wasn't on it. But the bus driver stopped, told me what happened, and i headed over to the school. When I got home I found several messages from the school on the answering machine.