Ohio Rev. Code § 5515.03
Occupants of land situated along the roads and highways of the state highway system shall remove all obstructions within the bounds of such roads and highways which have been placed there either by themselves or their agents, or with their consent, and not under a franchise or permit legally granted. By obtaining the consent and approval of the director of transportation, obstructions placed within the bounds of such roads or highways prior to January 2, 1928 may be permitted to remain upon the conditions prescribed in section 5515.01 of the Revised Code.
No individual, firm, or corporation shall place or maintain any post, sign, or obstruction within the bounds of any road or highway on the state highway system without first obtaining the consent and approval of the director.
R.C. §5515.03