Ohio Rev. Code § 5525.10
Except as provided in section 5525.15 of the Revised Code, no contract for any road improvement shall be awarded for a greater sum than the estimated cost thereof plus five per cent. The bids received for an improvement shall be opened at the time and place stated in the notice and the bids shall conform to such other requirements as the director of transportation prescribes. If no acceptable bid is made the director may readvertise the work at the original estimate or amend the estimate and again proceed to advertise for bids. The director may contract for the construction or improvement of bridges and culverts or the grading required in connection with an improvement and may defer making contracts for the remainder of said improvement until such grade has become stable and solid.
R.C. §5525.10