I've driven busses and I was never trained not to do this. This falls under common sense.

(in my country, to get a bus driver license, you have to go through training that explain how to act in weird situation, how to identify dangers and which danger to prefer. You have a whole hour about always stopping at a safe place (parking, bus stop, red lignt, stop sign) before getting involved with anything that happen inside)

In the US, in employment, there is no such thing as common sense. People come from diverse backgrounds. When you have a million employees, anything is possible as as an untrained baseline. Everything has to be trained.

Maybe not common sense, but if you have a drivers license you should absolutely know it