Alcohol Use and CDL Driving

The numbers are simply staggering! Every day, almost 30 people in the United States die in drunk-driving crashes. That calculates out to one person every 50 minutes, according to statistics collected by the National Highway Traffic Safety Association as part of the U.S. Department of Transportation. 


The number of deaths have fallen by a third in the last three decades, but the statistics still show that drunk-driving crashes claim more than 10,000 lives per year. We can do better.


Understanding how alcohol impairs the body and brain is paramount to reducing these numbers and making the roads safer for everyone. 

Measuring BAC and the Impact on the Brain

As the amount of alcohol in a person’s bloodstream increases, there are severe negative effects on the central nervous system. For example, it can impair thinking, reasoning and muscle coordination. All these abilities are essential to operating a vehicle safely.


Alcohol level is measured by the weight of the alcohol in a certain volume of blood. This is called Blood Alcohol Concentration, or BAC. At a BAC of .08 grams of alcohol per deciliter (g/dL) of blood, crash risk increases exponentially. Because of this risk, it’s illegal in all 50 states, the District of Columbia and Puerto Rico to drive with a BAC of .08 or higher. BAC is measured with a breathalyzer, a device that measures the amount of alcohol in a driver’s breath, or by a blood test. (Source: Dept of Transportation) 

Drunk Driving Regulations for CDL Drivers 

Every state in the U.S. has a blood alcohol limit of .08% for regular motorists, as mentioned above. For truck drivers with a CDL, the limit is cut in half. You can receive a DUI or DWI for a blood alcohol concentration of only .04%. This means that even a single beer can trigger an expensive legal charge and cause major disruption in your life and career.

According to Federal Motor Safety Carrier Administration regulations, a commercial driver may not use alcohol within four hours of going on duty or operating a commercial vehicle. Drivers can’t possess alcohol in the cab, and any driver who appears to have consumed alcohol in the past four hours must be placed off duty for 24 hours.

Each trucking company will have strict guidelines on when alcohol is allowed and when it is not. Our service here at Clearinghouse Navigator is meant to help facilitate testing and eLearning classes that can help inform and educate about these regulations.