RSA 265:56: School Bus Signs.

No school bus used for the purpose of transporting school children shall be driven upon the ways of the state unless it carries the designation "School Bus" in a conspicuous place showing to the front and rear thereof in lettering not less than 8 inches in height, and has such other distinguishing marks as the director may prescribe. When a school bus is being driven upon a way for purposes other than the transportation of school children, all designating marks thereon indicating school bus shall be covered or concealed.