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 New York State, it is indeed a criminal offense for a commercial vehicle operator to have a blood alcohol concentration (BAC) of .04 or higher, which is in accordance with federal regulations. This limit is indeed lower than the .08 BAC limit for non-commercial drivers. For holders of a Commercial Driver's License (CDL), the consequences of a DUI/DWI are particularly severe. A first offense can lead to a one-year suspension of the CDL, which can be a significant professional setback given their reliance on the license for employment. If a CDL holder commits a second DUI/DWI offense, they face the possibility of a lifetime disqualification from holding a CDL. These regulations are designed to promote safety on the roads and are typically found in the state's Vehicle and Traffic Law. It's important for CDL holders to be aware of these stringent standards and the potential impact on their career.