Not really sure about how the DUI thing is for the average driver. If one has a commerical drivers license, the penalties are a little stiff. And even if you are driving your car! A person with a CDL cannot have one beer, count it, one beer in an hour to trip the BAC limit on commercial drivers license regulations. Folks think .08 is a little stiff? Try .03 for a person with a CDL. And if caught, commercial license is suspended for at least 1 full year and you just kissed your career goodbye. Well, in a year or two or more, you might get a job with a garbage hauler in your area.
And it is even more fun. Just 2 times of getting caught going 15 mph over speed limit in a 3 year period, Commercial license is gone for 60 days. 3 times in 3 years, and CDL gone for 120 days. And there are several other categories of "serious" violations that will cause similar suspension or revocation. And even if they violations in question occur in your personal auto! That is because a CDL driver is also required to file annually a statement about all moving violations you receive in ANY vehicle. You fail to report, and you lose the commercial license. Either way, you rack of violations and the career hits the skids.
And this is dictated by Federal regulations, so the states have nothing to do with the penalties. They just enforce them. And the liability thing with motor carriers, along with their insurance carriers holding their feet to the fire, if a driver fits into the above situations, the career is gone. No reputable carrier will let you in the door, let alone a truck.