Bus operators will often find it economical to convert retired buses to use as permanent training buses for driver training, rather than taking a regular service bus out of use. Some large operators also converted retired buses into tow bus vehicles, to act as tow trucks.
Explain to an 8 year old child that is not yet 49 tall that the safety equipment built into the vehicle is for adults  not children, and a child needs to continue to use the proper equipment (booster seat) so that the adult equipment will fit, and be able to protect, their bodies in the event of a crash.
The laws vary based on age, height, and/or weight. For example, several states allow children the age of six and up or over 40 pounds to use the regular seatbelt without a booster seat. But as Elliott.org points out, there are safer guidelines from SafeKids.org regarding not just weight but height: Kids should be at least 4â9â tall and weigh at least 80 pounds before transitioning out of the booster. The American Academy of Pediatrics says kids between 8 and 12 years of age should be in booster seats.