(a) No person shall drive a commercial motor vehicle, as defined in Ohio R.C. 4506.01, or a commercial car or commercial tractor, as defined in Ohio R.C. 4501.01, while the person's ability or alertness is so impaired by fatigue, illness or other causes that it is unsafe for the person to drive the vehicle. No driver shall use any drug which would adversely affect the driver's ability or alertness.
(b) No owner, as defined in Ohio R.C. 4501.01, of a commercial motor vehicle, commercial car or commercial tractor, or a person employing or otherwise directing the driver of the vehicle, shall require or knowingly permit a driver in any such condition described in division (a) of this section to drive the vehicle upon any street or highway.
(c) Except as otherwise provided in this division, whoever violates this section is guilty of a minor misdemeanor. If the offender previously has been convicted of or pleaded guilty to one or more violations of this section or Ohio R.C. 4511.79, or Ohio R.C. 4511.63, 4511.76, 4511.761, 4511.762, 4511.764 or 4511.77, or a municipal ordinance that is substantially equivalent to any of those sections, whoever violates this section is guilty of a misdemeanor of the fourth degree.
(ORC 4511.79)