Ohio Rev. Code § 5525.15
The director of transportation may provide that prior to the bid opening, the official engineer's estimate of cost of any project to be constructed by the department of transportation shall be confidential information. After the bid opening, only the total official engineer's estimate of cost may be published.
The unit price components and the estimate of cost of any particular item of work involved therein shall be kept and regarded by the director and all the director's subordinates as confidential, and are not public records for purposes of section 149.43 of the Revised Code. This section does not prohibit the department from furnishing unit price components and the estimate of cost for any particular item of work involved therein to the federal government, counties, municipal corporations, or other local political subdivisions or to railroad or railway companies proposing to pay any portion of the cost of an improvement. Planning estimates are those estimates created for management of the capital program of the department and are public records for purposes of section 149.43 of the Revised Code.
Section 5525.10 of the Revised Code, which provides that no contract for any improvement shall be awarded for a greater sum than the estimated cost thereof plus five per cent, does not apply in the case of any project with respect to which the authority conferred by this section is exercised. In cases in which the authority conferred by this section is exercised and in which the bid of the successful bidder exceeds the estimate, the director, before entering into a contract, shall determine that the bid of the successful bidder is fair and reasonable, and as long as the federal government imposes regulation on prices charged for construction service, shall require the successful bidder to certify that the bidder's bid does not exceed the maximum permitted by such federal regulation.
R.C. § 5525.15