by Lisa Frederiksen
One question I’m regularly asked is whether a person 
can be arrested for DUI if they have “a couple of drinks” and then wait a while before they drive — especially if their blood alcohol (BAC) is below .08. The short answer is, “yes.” It takes the body an AVERAGE of about one hour to metabolize one drink; 3 drinks – 3 hours. The longer answer is that it is against the law to drive while impaired. In California, for example, there are two DUI charges that are possible should a police officer pull you over:
- the 1st is for driving while under the influence of alcohol (or drugs) to the extent that you are “unable to drive [your] car with the same caution characteristic of a sober person, of ordinary prudence, under the same or similar circumstances,” and
- the 2nd is focused purely on body chemistry — the BAC. This is one based on the breathalizer test, for example, where the police officer conducts the test and records your BAC. Whether the driver was driving ‘perfectly’ before being pulled over or passed the field sobriety tests with flying colors does not matter. The only thing that matters is the BAC number of .08 or higher.
How does the prosecution in a DUI drugs case go about proving that alcohol (or drugs) impaired the driver’s abilities to the extent necessary to support a conviction when the BAC is below .08? The same way they do any criminal case based on circumstantial evidence, such as: the manner in which the car was driven, the physical signs and symptoms of the driver, the driver’s performance on field sobriety tests (the “touch your nose,” “walk a straight line” types of tests), the results of the driver’s blood or urine tests and/or the testimony of a alcohol or drug recognition expert.
Below are a few excerpts from the CA DMV chart to help you see where your BAC might fall after having “a couple of drinks” and then driving:
110-129 lbs: 1 hour or less since your first drink and you consume 2 or more drinks, your BAC is probably .08% or higher
130-149 lbs: 2 hours or less since your first drink and you consume 3 or more drinks, your BAC is probably .08% or higher
170-189 lbs: 2 hours or less since your first drink and you consume 4 or more drinks, your BAC is probably .08% or higher
