You probably know that every state has laws about driving while intoxicated. For most people, the limit is .08% blood alcohol content. This level is when the majority of people will be far too impaired to drive safely.
For truck drivers, the laws are a little bit different. If they are behind the wheel, it’s expected that they won’t have a BAC over .04%. Why? The vehicles are larger and more likely to cause serious damage in a collision.
Trucking regulations do look at drunk driving differently and require that drivers have half or less of the usual BAC limit if they’re driving. This is a safety protocol because it is much less likely that the driver will be impaired at .04% compared to .08%.
At the same time, other laws and regulations make it so that most drivers should never be behind the wheel with a high blood alcohol content. The Federal Motor Carrier Safety Administration, or FMCSA, states that commercial drivers are not allowed to operate their vehicles or go on duty within four hours of drinking alcohol. They also are not allowed to have alcohol in the main cab.
On top of that, and a lesser-known rule, is that drivers who have had a drink within four hours before their shift have to be placed off-duty for at least 24 hours as a safety precaution.
To review, the truck driver may not drink when they are waiting at a terminal, having their vehicle inspected, repairing their vehicle, loading or unloading the truck or are in the truck. The only exception is that they may have a drink and then rest in the vehicle, so long as they will not be driving for at least four hours following that beverage.
Trucking companies may have their own rules as well because the last thing they want is a driver causing a DUI crash that ends up painting the company in a bad light. If they do cause a crash, they will need to build a strong defense to protect their commercial driver’s license and keep their job.