Driving under the influence (DUI) charges in Georgia are serious, but the laws for alcohol and drug DUIs differ significantly. Knowing these differences can help you understand the legal process and potential defenses.

The Legal Limit: Alcohol vs. Drug DUI

Alcohol DUI: A Clear Standard

In Georgia, an alcohol DUI is defined by a straightforward legal limit: a blood alcohol content (BAC) of 0.08 or higher. If your BAC exceeds this threshold, the law presumes impairment, and you are automatically considered guilty of DUI.

Drug DUI: No Set Limit

Unlike alcohol, drug DUIs have no legal limit. Prosecutors need only show that a driver had drugs in their system and that these drugs rendered them less safe to drive. This makes drug DUI cases more subjective and harder to prove, as they rely heavily on connecting drug presence to actual impairment.

Evidence Used in DUI Cases

Alcohol DUI Evidence

Alcohol DUI cases typically rely on measurable evidence, such as:

• Breathalyzer results: Showing a BAC of 0.08 or higher

• Field sobriety tests: Assessing coordination and focus

• Behavioral observations: Slurred speech or unsteady movements

Drug DUI Evidence

Drug DUI cases, in contrast, involve:

• Blood or urine tests: Detecting drug presence

• Field sobriety tests: Horizontal Gaze Nystagmus (HGN), walk-and-turn, and one-leg stand tests

• Expert testimony: Often from toxicologists interpreting lab results

Unlike alcohol DUIs, drug DUIs require proof that the substances in the driver's system caused impairment. This can make these cases more complex and open to legal challenges.

License Penalties: Alcohol vs. Drug DUIs

Alcohol DUI: Shorter Permit Period

For an alcohol DUI conviction, Georgia drivers face a 120-day limited driving permit. After completing this period and meeting additional requirements, such as attending a risk reduction program, drivers may regain full driving privileges.

Drug DUI: Longer Permit Period

A drug DUI conviction results in a 180-day limited driving permit—two months longer than for alcohol DUIs. This reflects the state's stricter stance on drug-impaired driving.

Defense Strategies for Drug DUIs

Challenging Scientific Evidence

One of the most effective strategies in drug DUI cases is to challenge the prosecution's evidence. Unlike alcohol, for which BAC levels are well-studied, drug impairment lacks clear scientific thresholds. Defense attorneys often file Daubert motions to question the validity of expert testimony.

For example, if the prosecution claims that a certain amount of marijuana in your system proves impairment, your attorney can argue that this conclusion lacks scientific backing. Successfully excluding such evidence can significantly weaken the case against you.

Field Sobriety Tests and Their Role

Field sobriety tests are often used in DUI cases but are less reliable for drugs:

• HGN test: Detects central nervous system depressants like alcohol but is less effective for marijuana

• Walk-and-turn test: Evaluates divided attention and the ability to follow instructions, which can be impaired by drugs

• One-leg stand test: Measures balance and coordination, often affected by drug use

These tests can be challenged in court, especially if they were not administered correctly or if the results are interpreted inconsistently.

Final Thoughts

The main difference between alcohol and drug DUIs in Georgia lies in the legal limit: while alcohol DUIs have a defined threshold (0.08 BAC), drug DUIs do not. Prosecutors must show that drugs in a driver's system directly caused impairment. This makes drug DUI cases more subjective but also provides more opportunities for defense.

If you or a loved one are facing DUI charges, it's crucial to have experienced legal representation on your side. Contact Brett Willis Law today to discuss your case and explore your options. With the right legal strategy, you can challenge weak evidence and potentially reduce or eliminate charges.