In many states it is a criminal offense (DUI/DWI) to operate a commercial vehicle with a blood alcohol concentration of .04 or more—which is half of the BAC usually required to commit the DUI/DWI offense while driving a non-commercial vehicle. Because most holders of commercial driver’s licenses (CDLs) depend on their license to earn a living, the consequences of a DUI/DWI conviction for a CDL holder—including a conviction while operating a non-commercial vehicle—are serious.

Laws vary from state to state but a CDL holder’s license may be suspended for one year for the first offense, and with a second DUI/DWI conviction the CDL holder may be permanently disqualified from holding a CDL.

These laws are generally located in a state’s statutes—often in the vehicle code, motor vehicle code, or transportation code.

In Ohio, it is indeed a criminal offense for a commercial vehicle operator to have a blood alcohol concentration (BAC) of .04 or higher, which is indeed half the BAC limit for non-commercial drivers. Ohio law is strict with CDL holders because of the potential for greater harm due to the size and weight of commercial vehicles. For a first DUI/DWI offense, a CDL holder can face a one-year suspension of their commercial driver's license. If the offense involves transporting hazardous materials, the suspension period can extend to three years. A second DUI/DWI conviction can lead to a lifetime disqualification from holding a CDL, which can be reduced to 10 years under certain conditions. These regulations are designed to ensure the safety of the roads and hold commercial drivers to a higher standard of responsibility. The specific laws governing these penalties are typically found in the Ohio Revised Code, particularly in the sections related to motor vehicles.