Ohio Rev. Code Ann. § 4506.03
(A) Except as provided in divisions (B) and (C) of this section, the following shall apply:
(1) No person shall drive a commercial motor vehicle on a highway in this state unless the person holds, and has in the person's possession, any of the following:
(B) Nothing in division (A) of this section applies to any qualified person when engaged in the operation of any of the following: