Ohio Rev. Code § 4511.105
Tourist-oriented directional signs shall conform to the specifications contained in the manual of uniform traffic control devices.
If more than one eligible attraction requires a sign at the same location, multiple signs may be combined on the same panel in accordance with the manual of uniform traffic control devices.
Advance signing may be installed in those situations where sight distance, intersection vehicle maneuvers, or other vehicle operating characteristics require advance notice of an eligible attraction in order to reduce vehicle conflicts and improve highway safety.
The design, arrangement, size, and location of tourist-oriented directional signs, including advance signs and trailblazer markers, authorized under sections 4511.102 to 4511.105 of the Revised Code shall conform to the applicable specifications contained in the manual of uniform traffic control devices.
R.C. § 4511.105