During the first five years of existence for all purposes of a unified school district formed under the provisions of Article 1 or Article 2 of Chapter 2 of Part of the Education Code, the Superintendent of Public Instruction may approve the replacement of more than one small bus with a single larger unit if he determines that the efficiency of operation of the transportation system will be increased or that operational costs will be decreased by such replacement. The approval shall be subsequent to, and justified by, a review of the district's transportation system including fleet size, schools, routes, pupils transported, and related current expense of operation.
Cal. Code Regs. Tit. 5, § 15322