The primary vehicle used for student transport in North America, school buses are distinguished from other types of buses by design characteristics necessitated by federal and state/provincial regulations. Federal safety standards require school buses to be painted school bus yellow and equipped with specific warning and safety devices. This service is almost always provided without charge to families. In other parts of the world, the term “school bus” refers more to the destination of the bus and its student passengers than the specific vehicle designed for that purpose; the vehicles used for student transport are more closely related to other types of buses than their North American counterparts.
Not all of them are like this, of course, but still I think I’d prefer to do without the “federal regulation” aspects of design.