California DUI Laws Are Strict For Those Holding A Commercial Driver’s License


A big rig carrying a load of steel beams and a crane flipped over on the 101 near San Rafael this past week. The accident, which blocked three of the four lanes, happened at 8 a.m. during the height of rush hour on a Monday morning. Yes, big rigs flip over, our freeways get blocked, sometimes even during rush hour. But there was something striking about this accident: the driver of the big rig had a blood alcohol level at five times the legal limit for commercial drivers. At 8:00 in the morning! Now, that is frightening. Miraculously, no one was seriously injured or killed. The driver was booked on felony DUI charges and. If convicted, he will probably be searching for a new line of work once he serves his sentence.

Although we normally think of the DUI blood alcohol content (BAC) threshold as .08%, for commercial-licensed drivers the limit is lower. Anyone who holds a commercial driver’s license is considered DUI if his or her BAC is .04% or higher. If a driver with a commercial license is convicted of driving with a BAC of over .04%– even if the driver wasn’t driving a commercial vehicle at the time of the DUI arrest—his or her commercial driver’s license will be suspended for at least one year (three years if driving a vehicle carrying hazardous materials). This is a straight suspension on the commercial license, no exceptions. If it is the commercial-licensed drivers second DUI for driving at .04% BAC or above, the law requires that the commercial driver’s license be revoked for life. These laws apply to a commercial driver who is driving under the influence of drugs also.

Commercial drivers include not only big-rig drivers, but bus drivers, drivers who carry more than 10 passengers, certain delivery drivers and others. For most commercial drivers, their livelihood depends on a valid commercial driver’s license. So, when a driver who holds a commercial driver’s license is convicted of a DUI—even if he or she was not driving a commercial vehicle at the time of the arrest­— at one-half the BAC allowed for non-commercial licensed drivers, the driver not only loses his or her license for a year, but will probably lose his or her job.

In the case of the San Rafael big-rig driver, he and his passenger were injured, although not seriously. A commercial DUI with injury can be charged as a felony and a conviction on that charge can result in a prison sentence. Additionally, this driver’s high BAC level is considered an aggravating factor, which carries enhanced penalties. Considering the circumstances, the prosecutor is likely to throw the book at him. And there is no question that this big-rig driver needs to be taken off our roads.

William Weinberg has almost 25 years of experience in defending drivers charged with driving under the influence. You may consult with him about your DUI matter by contacting him at his Irvine office at 949-474-8008 or emailing him at