Actually, Columbus would not be the first in Ohio to use Uni-signs.
Uni-signs have been used for over 20 years in Mahoning County (Youngstown) mostly by the county engineers.
I don't have any pictures, but most of the ones I remember seeing are those approaching state/US routes. Reading top-to-bottom, the sign would say:
I also dare to say that to the north of Youngstown, uni-signs are rare, but used sparingly in Trumbull and Ashtabula Counties as well.