There are two different charges one can receive for a DUI - 23152 (a) and 23152 (b) of the vehicle code. (a) is for driving under the influence, that is the charge that makes it illegal to drive under the influence of alcohol, drugs or a combination of the two. It has nothing to do with the blood alcohol level, one can be a complete lightweight and have a blood alcohol of 0.04% which is half the legal limit, but if you were driving recklessly you can be arrested and convicted of 23152 (a). (b) makes it illegal to drive with a blood alcohol level of 0.08% or higher. This particular charge has nothing to do with how one is driving. For instance you can be pulled over for a burnt out taillight and officers can determine you were at or above 0.08% blood alcohol level to be charged for 23152 (b).