Ohio Rev. Code § 153.32: Contracts for erection and repair of superstructures.

When it becomes necessary to erect a bridge, the board of county commissioners shall determine the length and width of the superstructure, and whether it shall be single or double track, and it shall advertise for bids for performing the labor and furnishing the materials necessary to the erection thereof in accordance with sections 307.86 to 307.92 of the Revised Code.