Me. Rev. Stat. tit. 29-A, § 2311

The Commissioner of Education may adopt or amend rules consistent with this Title and in accordance with the Maine Administrative Procedure Act, concerning school bus construction, equipment, operation and identification. Should the Federal Government or the State require transportation of public preschool children, the Department of Education shall develop and adopt rules regarding such transportation, and those rules are major substantive rules as defined in Title 5, chapter 375, subchapter 2-A.