Ohio Rev. Code § 5547.04
The owner or occupant of lands situated along the highways shall remove all obstructions within the bounds of the highways, which have been placed there by them or their agents, or with their consent.
By first obtaining the consent and approval of the board of county commissioners, obstructions erected prior to July 16, 1925 in highways other than roads and highways on the state highway system or bridges or culverts thereon, may be permitted to remain, upon such conditions as the officials may impose, provided such obstructions do not interfere with traffic or with the construction or repair of such highways.
No person, partnership, or corporation shall erect, within the bounds of any highway or on the bridges or culverts thereon, any obstruction without first obtaining the approval of the board in case of highways other than roads and highways on the state highway system and the bridges and culverts thereon.
All advertising or other signs and posters erected, displayed, or maintained on, along, or near any public highway, and in such a location as to obstruct, at curves or intersecting roads, the view of drivers using such highway, are obstructions, but this section has no application to crossing signs erected in compliance with section 4955.33 of the Revised Code, at the crossings of highways and railroads.
The board shall enforce this section and, in so doing, may avail itself of section 5547.03 of the Revised Code.
R.C. §5547.04