Of course the best way to avoid a DUI arrest is to not drink and drive or have a designated driver who does not drink and drive. However, it is legal to drink and drive as long as your blood alcohol is under .08% and your driving is not affected by the alcohol. For example, if you get in a car accident and your blood alcohol is .06%, you could still be charged with a DUI because the government will argue that your driving was affected by the alcohol even though it was under the legal limit.
There are numerous defenses to a DUI based on blood alcohol testing of .08% but the defenses are based on the particular set of facts in each case. For example, if you drank two drinks at a party and within the hour of drinking your second drink, you drove home and were arrested within the same hour of drinking the second drink, you could argue that at the time of driving you were not at .08% blood alcohol. This is called a “rising blood alcohol” defense.
This is a very hard defense to win and is based on the science behind the testing and timing of the blood alcohol in your case. The law in California, Vehicle Code section 23152(b) states that if your blood alcohol is .08% or above within three hours of driving, then you are guilty of violating the drunk driving laws. This defense may be brought if you were to take the cases to trial. It normally would not work before trial with the government attorney.
The rule of thumb is that one 4 ounce drink, whether it is wine or a mixed drink, with one shot of alcohol equals .04% blood alcohol. This does not take into account the weight of the drinker. The other rule of thumb is that most individuals, again not taking into account the weight of the drinker, is that you burn .02% blood alcohol per hour.
So in the above hypothetical, the individual who drank one 4 once drink with one shot of alcohol or one glass of wine at 6:00 pm, and drove at 8:00 pm, would have approximately .02% blood alcohol or less in their system. This is because the individual would have burned .02% blood alcohol per hour.
So, if you plan on drinking two glasses of wine or 2 mixed drinks with one shot of alcohol in each drink, the best way to make sure you will not violate the drunk driving laws of California and not be charged with a DUI is to make sure you wait at least two hours after your last drink before driving. For the average person, not taking into account the weight of the person, you would have at most .04% blood alcohol if you follow the above example. However, as stated above, if you are a person who never drinks and were to drive after two hours after consumption of your second drink and your driving was affected by the alcohol, you could still be charged with driving under the influence of alcohol.
The law in California also allows a prosecution of DUI with blood alcohol under .08% if your driving was affected by the alcohol in your system. California Vehicle Code section 23152(a). In addition, if you take any prescription medications and drank alcohol, you could be guilty of a driving under the influence. The key is that the police officer who pulled you over would have to document your driving and how it led the officer to believe the driver was affected by alcohol and/or alcohol and drugs. If you get into a car accident, that usually will allow the government to argue that your driving was affected by alcohol.