VC 23152(a)
(a) It is unlawful for any person who is under the influence of any alcoholic beverage or drug, or under the combined influence of any alcoholic beverage and drug, to drive a vehicle.
VC 23152(b)
(b) It is unlawful for any person who has 0.08 percent or more, by weight, of alcohol in his or her blood to drive a vehicle.
Note re VC 23152(a)
This law has given the police a lot of power as they can arrest and have someone charged with a DUI based simply on their opinion. If the officer thinks in his opinion you are under the influence of alcohol or a drug you can be charged with a DUI even if your breath or blood result is under .08 and you can be charged with a DUI even if you refused to take a breath or blood test. See Can I be under the limit and still get a DUI? for more detail.