Ohio Rev. Code § 5553.02
The board of county commissioners may locate, establish, alter, widen, straighten, vacate, or change the direction of roads as provided in sections 5553.03 to 5553.16 of the Revised Code. This power extends to all roads within the county, except that as to roads on the state highway system the approval of the director of transportation shall be had. However, no public road shall be located or established, by the board of county commissioners, unless the location or establishment begins on a public road and terminates on a public road, or begins on a public road and services a public park, a state supported educational institution, public school, public aviation area, or a public recreation area, or begins on a public road and services at least three private residences or businesses in the first five hundred feet and one private residence or business in each two hundred feet thereafter.
R.C. §5553.02