DUI / DWI

The short version

DUI (Driving Under the Influence) or DWI (Driving While Intoxicated) means operating a vehicle with impaired abilities, usually due to alcohol or drugs. These charges can lead to serious penalties, including losing your driver's license, fines, and even jail time. Understanding how these laws work helps you navigate the legal process if you are accused.

The law this is built on

Every point below comes from the authority named next to it. Verify the current text before relying on it.

State vehicle codes
Each state's vehicle code defines what constitutes driving under the influence or driving while intoxicated, including specific limits for blood alcohol content (BAC). It also outlines the penalties for these offenses.
Why it matters: These codes are the actual laws you must follow when driving in your state, and they determine the legal limits and consequences for impaired driving.
23 U.S.C. § 163
This federal law encourages states to adopt certain laws regarding impaired driving by offering federal highway funds as an incentive. One key incentive is for states to set the illegal blood alcohol concentration (BAC) limit at 0.08% for drivers aged 21 and older.
Why it matters: This federal law has led most states to adopt a 0.08% BAC limit, making it a common standard across the country for impaired driving.

Words you need to know

DUI/DWI: Driving Under the Influence (DUI) or Driving While Intoxicated (DWI) means operating a motor vehicle while your ability to drive is impaired by alcohol, drugs, or other substances. The specific term used can vary by state.
BAC (Blood Alcohol Content): BAC is a measure of the amount of alcohol in your blood, expressed as a percentage. In most states, a BAC of 0.08% or higher for drivers 21 and over is considered illegal, as outlined in state vehicle codes, influenced by federal law 23 U.S.C. § 163.
Implied Consent Law: When you get a driver's license, you automatically agree to take a chemical test (like breath, blood, or urine) if a police officer suspects you're driving impaired. Refusing this test often leads to immediate penalties, such as license suspension, even if you are not convicted of DUI/DWI.
Field Sobriety Tests (FSTs): These are a series of physical and mental exercises an officer might ask you to perform at the roadside to assess your impairment. Examples include walking in a straight line or standing on one leg.
Administrative License Suspension (ALS): This is a separate process from your criminal court case. Your driver's license can be suspended by the Department of Motor Vehicles (or similar agency) soon after a DUI arrest, often because of a high BAC or refusing a chemical test, based on state vehicle codes.

Your rights

✓You have the right to remain silent if questioned by police.
✓You have the right to refuse Field Sobriety Tests (FSTs), though police may still arrest you if they have probable cause.
✓You have the right to refuse a preliminary breath test (PBT), but refusing a lawfully requested chemical test after arrest often carries specific penalties under implied consent laws.
✓You have the right to speak with an attorney before answering questions after you are arrested.
✓You have the right to challenge the charges against you in court.

How the process actually works

1
Traffic Stop
When an officer observes suspicious driving or a violation.
An officer pulls you over for a traffic violation or suspicion of impaired driving. They may observe signs like weaving or erratic driving.
2
Investigation
Immediately after the stop.
The officer will ask you questions, look for signs of impairment (like odor of alcohol, slurred speech), and may ask you to perform Field Sobriety Tests (FSTs) or take a Preliminary Breath Test (PBT).
3
Arrest
Following probable cause of impairment.
If the officer believes they have probable cause that you are driving impaired, they will arrest you. At this point, you may be asked to take an official chemical test (breath, blood, or urine) at the station.
4
License Suspension (Administrative)
Often within hours or days of arrest.
Your driver's license may be immediately confiscated and suspended by the Department of Motor Vehicles (or equivalent state agency) due to a high BAC or refusal of a chemical test, as defined by state vehicle codes.
5
Criminal Charges Filed
Varies by state, can be days or weeks after arrest.
The prosecutor reviews the evidence and officially files criminal charges against you for DUI/DWI.
6
Court Process
Varies by state, weeks to months after charges are filed.
You will go through court proceedings, which may include arraignment, pre-trial hearings, negotiations, and potentially a trial. Your attorney will represent you.

Deadlines that can end your case

Request Administrative Hearing
Varies by state (often 7-30 days)
If you miss this deadline, you usually lose your right to challenge the administrative license suspension, meaning your license suspension will take effect automatically.
Plead Guilty/Not Guilty
At arraignment (often within a few weeks of arrest)
This is your first formal opportunity to enter a plea in the criminal case. Missing it can result in a warrant for your arrest or a default judgment.

Costly mistakes

✕Answering police questions after arrest without an attorney present.
✕Failing to understand the difference between administrative license suspension and criminal court cases.
✕Missing deadlines for requesting administrative hearings, which can lead to automatic license suspension.
✕Believing that refusing a chemical test will prevent a DUI charge or avoid penalties.
✕Driving with a suspended license, which can lead to additional criminal charges and penalties.
✕Not understanding that some medications, even if prescribed, can impair your driving and lead to a DUI.

Your checklist

Understand the implied consent laws in your state if you are stopped.
Know your right to refuse Field Sobriety Tests (FSTs).
If arrested, clearly state you wish to speak with an attorney.
Gather all paperwork received from the police and court.
Contact an attorney immediately after a DUI arrest.
If your license is suspended administratively, be aware of the deadline to request a hearing to challenge it.

Common questions

What is the legal BAC limit?

In most states, the legal blood alcohol content (BAC) limit for drivers 21 and older is 0.08%. This is largely due to federal incentives for states to adopt this standard, as noted in 23 U.S.C. § 163. For commercial drivers or those under 21, the limit is often lower or zero.

What happens if I refuse a breathalyzer test?

Under implied consent laws, refusing a lawfully requested chemical test (like a breathalyzer, blood, or urine test) after a DUI arrest typically results in an immediate administrative license suspension. This penalty is separate from any criminal DUI charge and happens even if you are not ultimately convicted of DUI, as per state vehicle codes.

Can I get a DUI for driving under the influence of drugs?

Yes, state vehicle codes broadly define impaired driving to include impairment from drugs (legal or illegal), not just alcohol. If drugs impair your ability to safely operate a vehicle, you can be charged with DUI/DWI. This is often called 'DUID' (Driving Under the Influence of Drugs).

Will I lose my driver's license?

A DUI/DWI charge almost always involves a driver's license suspension. This can happen in two ways: an immediate administrative suspension by the DMV (due to high BAC or test refusal) and a separate suspension if you are convicted in criminal court, both outlined in state vehicle codes.

How this changes by state

DUI/DWI laws can vary significantly from state to state, including specific definitions of impairment, BAC limits for different driver groups, mandatory penalties, and processes for challenging license suspensions. While 23 U.S.C. § 163 encourages a 0.08% BAC limit, other aspects like minimum jail time, fine amounts, and license reinstatement requirements are set by individual state vehicle codes. To find your state's specific rules, you should consult your state's Department of Motor Vehicles (DMV) website or vehicle code statutes.

When you need a lawyer

You should consider hiring a lawyer immediately if you are arrested for DUI/DWI. The legal process is complex, involves both administrative and criminal penalties, and deadlines are strict. A lawyer can help you understand your rights, challenge evidence, negotiate with prosecutors, and navigate the entire process, including preserving your driving privileges.

Do this today

→If arrested, review all documents provided by law enforcement and the court.
→Note all deadlines, especially for administrative license suspension hearings.
→Contact an attorney experienced in DUI/DWI cases in your state as soon as possible.

This lesson is legal information for educational purposes only, based on State vehicle codes; 23 U.S.C. § 163. It is not legal advice and does not create an attorney-client relationship.