Ohio Revised Code Title LV. Roads Highways Bridges § 5555.72

When the board of county commissioners constructs, reconstructs, widens, resurfaces, repairs, or improves a road by force account, and the estimated cost of the work, as defined in section 5543.19 of the Revised Code, exceeds three thousand dollars per mile, such board shall cause to be kept by the county engineer a complete and accurate account in detail of the cost of doing such work. Such account shall include labor, materials, freight, hauling, fuel, and all other items of cost, including a reasonable allowance for the use of tools and equipment owned by the county and for depreciation on such tools. The engineer shall keep such account, and within ninety days after the completion of any such work he shall prepare a detailed and itemized statement of such cost and file it with the board, which shall thereupon examine such statement, correct it if necessary, and cause such statement to be filed in its office. Such statement shall be kept on file for not less than two years and shall be open to public inspection.