Ohio Rev. Code Ann. § 5559.03

When a petition is presented to the board of county commissioners asking for the improvement as provided by section 5559.02 of the Revised Code, and specifying the general character of the improvement desired, signed by at least fifty-one per cent of the land or lot owners, residents of such county, who are to be specially assessed for such improvement, the board shall, within thirty days after such petition is presented, go upon the line of the proposed improvement, and, after viewing it, determine whether the public convenience and welfare require that such improvement be made.