Haw. Code R. § 8-28-2
As used in this chapter:
"Department" means the department of education.
"Parent" means the natural or legal parent, guardian or other legal custodian of the student.
"Principal" means the principal of the school the student attends or the principal's designee.
"School bus" means any publicly or privately owned motor vehicle used to transport pupils to and from a school as defined in section 298-41, Hawaii Revised Statutes, or school functions or school related events except:
(1) A motor vehicle used for transportation of students attending schools above the twelfth grade or pupils over eighteen years of age;
(2) A privately owned passenger vehicle when the transportation is provided without compensation of any kind; or
(3) A motor vehicle used for transportation of pupils together with other passengers as a part of the regularly scheduled operation of a mass transit system.
"Student" means students in grades kindergarten through twelve and in special education classes who are passengers in a school bus that is under contract with or operated by the State.
Haw. Code R. § 8-28-2