Ohio Rev. Code § 3327.012
Payments to school districts for transportation of school pupils shall be made on a current basis according to an estimate which shall be filed with the department of education and workforce by respective school districts in accordance with rules which the department shall promulgate. The sum due the respective school district as calculated from approved cost in accordance with the rules of the board of education shall be adjusted annually in the quarter next following the end of the school year. The department may contract with any firm, person, or board of education to provide pupil transportation services authorized by this section. In no event shall the payment for such contract service exceed the average transportation cost per pupil, such average cost to be based on the cost of transportation of children by all boards of education in Ohio during the next preceding year.
R.C. § 3327.012