There are many different ways that a driver can be charged with DUI in the state of Georgia.

You must be driving or in actual physical control of a moving vehicle in order to be charged.  Under Georgia law, the offense can occur on public roads or on private property.  Being behind the wheel with the keys in the ignition and the radio or heater on may be enough to qualify as "actual physical control."

The safest thing to do is to stay out from behind the steering wheel if you have had anything to drink or have any medication or drugs in your system.    However, particularly when speaking of medication, that is not always possible.

There are then two sets of alternatives in which a person can then commit DUI:

Less Safe Offenses

It is a violation of Georgia law to be driving or be in actual physical control of a moving vehicle while under the influence of one or more of the following to the extent that the person is "less safe."

• Alcohol
• Drugs or Medications
• intentional influence of any glue, aerosol, or other toxic vapor ("huffing")

Per Se Offenses

There are several per se offenses in Georgia.

• It is a violation of Georgia law to have an alcohol concentration of 0.08 (0.10 before July 1, 2001) grams percent or more within three hours of driving or being in actual physical control of a motor vehicle from alcohol consumed prior to or at the time of driving.
• It is a violation of Georgia law to have an alcohol concentration of 0.04 grams percent or more while driving or being in actual physical control of a moving commercial motor vehicle.
• It is a violation of Georgia law to be under the age of 21 and have an alcohol concentration of 0.02 grams percent or more within three hours of driving or being in actual physical control of a motor vehicle from alcohol consumed prior to or at the time of driving.
• It is a violation of Georgia law to have present in the person's blood or urine any marijuana or controlled substance, including any metabolites or derivatives, whether or not there is any alcohol usage. However, the portion of the statute dealing with marijuana has been declared unconstitutional. It is currently unsettled as to whether other "controlled substances" also fall afoul of the equal protection clause. That distinction will turn upon the legal availability of the particular controlled substance.

Additional Offenses

A person also commits a DUI offense by being DUI as set out above and having a minor child under the age of fourteen (14) years in the vehicle.  This offense is counted as a DUI for purposes of license suspension issues. For instance, a parent  transports two under-14-year-old children to school and is stopped and charged with DUI, because the police believe that the parent is impaired, even a lawfully prescribed and used prescription, the parent could be charged with DUI and two counts of Endangering a Child by DUI.  If the person pleads guilty to the three offenses, the driver would be declared to be a habitual violator, have the driver's license revoked for five years and with only limited opportunity to get a permit after two years.

Evidence Issues

As far as admissable alcohol test results, the following evidentiary inferences may be considered by the judge or jury that hears your case:

0.05 grams percent or less                                                                                        The jurors may infer that the person is not under the influence of  alcohol

in excess of 0.05 grams percent but less than 0.08 grams percent or less               No inference as to whether the person is under the influence of alcohol shall arise from the alcohol test result

0.08 grams percent or more                                                                                       It may be inferred that the person is under the influence of alcohol.

If the alcohol test shows the alcohol concentration is 0.08 grams percent or more, this is a per se violation as discussed above if it is properly charged against you 

Under 21 is a Special Case

Because of the very low reading which can result in a conviction for an under-21-year-old driver, 0.02 grams percent, some special attention should be paid.  

If the person has not consumed any alcohol within a relevant period, then they should probably take a requested breathtest because the assumption is that they will blow 0.0 grams percent.  How much alcohol in a relevant period of time may be difficult to figure out.  If the person has had no alcohol in 24 hours, then they should be safe to blow in either or both of the field test and the official breath test.  Since, you generally add 0.02 for each drink, but only metabolize the alcohol at 0.015 per hour, there is some calculation needed.

To get to zero BrAC from one standard drink, the waiting period is around one hour and twenty minutes.

For two drinks, the waiting period increases to two hours and forty minutes.

Three drinks means you need 4 hours.  The more that you drink, the longer the waiting period.

It is also worth noting that if the officer requests a blood or urine test, the advice may change depending on whether the person has consumed any illegal drug within a period during which that substance could still show up on a blood test.  As I said earlier, all of this is very complicated for the person on the side of the road.

The General Advice

The general advice is to say no to field sobriety tests, roadside blows and the official state test if the person has consumed any alcohol, any illegal drug, or any prescription medication not prescribed to the person.