DUI vs. DWI vs. OUI: Is There a Difference?

You’re likely familiar with references to driving under the influence (DUI) or driving while intoxicated/impaired (DWI). Perhaps you’ve also heard of operating under the influence (OUI). These are all legal terms used in the United States to describe the offense of driving while impaired by, or under the influence of, drugs or alcohol. Although they all relate to similar behavior, the exact meaning and use of each term can vary.

In this article, we’ll break down each of these terms and explore their similarities/differences. We’ll also dispel common misconceptions and answer some frequently asked questions related to these offenses.

State law governs in this area. So, if you’re facing any of these charges, you’ll want to speak with a DWI/DUI attorney licensed in your jurisdiction. They can help you understand your options and mitigate potential consequences.

DUI vs. DWI

DUI and DWI are often used interchangeably, but the main difference lies in the terminology used by different states.

What Does DUI Mean?

DUI stands for “driving under the influence.” This is the most commonly used term across the United States. It means that a person was caught driving a vehicle while under the influence of alcohol, drugs, or any other substance that affects their ability to drive safely.

Many states regard a blood alcohol content (BAC) of 0.08% or higher as being under the influence of alcohol.

But DUI doesn’t only refer to drunk driving. It can also include driving under the influence of drugs (legal or illegal) and other substances.

In most states, the vehicle must be moving for DUI charges. But, there are some situations where it’s possible to get a DUI in a parked car.

What Does DWI Mean?

DWI stands for either “driving while intoxicated” or “driving while impaired,” depending on the state. Some states use DWI for driving under the influence, similar to DUI. Others may use both terms, but for different levels of impairment.

In North Carolina, for example, DWI means driving while noticeably impaired or with a BAC of 0.08% or higher. It treats DUI as a charge for lesser offenses like impairment that doesn’t meet the full DWI threshold or underage drinking and driving.

Texas law uses DWI for adults and DUI for minors (people under 21) who have any alcohol in their system.

Some places that use both terms reserve DWI for the more serious charges. In others, it’s the opposite.

For example, Maryland treats DUI as the more serious charge, and DWI is used for people who are slightly impaired (with a blood alcohol concentration between 0.07% and 0.079%).

Like DUI, a DWI charge usually means the car was moving while the driver was impaired. However, many states are also able to bring DUI/DWI charges if someone is in “physical control” of a vehicle, even if they aren’t moving.

What Does OUI Mean?

OUI stands for “operating under the influence.” It’s less common than DUI and DWI, but some states like Massachusetts and Maine use this term.

In OUI states, “operating” means someone doesn’t have to be actually driving to be charged. Just sitting in the driver’s seat with the engine running, or even with the keys in the ignition, can count as operating the vehicle.

Like DUI and DWI, OUI covers both alcohol and drugs.

What About OWI and Other Terms?

States most frequently use DUI and DWI to mean driving while impaired. But you may see references to other less common legal terms. These might include:

• Operating while intoxicated (OWI): Criminal offense in Indiana, Iowa, Michigan, and Wisconsin for operation of a vehicle while impaired by any substance
• Driving while ability impaired (DWAI): Usually a less serious charge that applies when someone’s driving is affected by alcohol/drugs, but their substance levels are below the legal limits
• Operating a vehicle under the influence of an intoxicant (OVUII): Hawaii’s unique and highly specific version of OUI/OWI
• Driving under the influence of intoxicants (DUII): Oregon’s DUI/DWI charge
• Operating a vehicle while impaired (OVI): Ohio’s version of OUI/OWI, applicable to motorized and non-motorized vehicles

Other states may also allow these charges for non-motorized vehicles like bicycles or horses. This depends primarily on how their laws define key terms like vehicle, driving, and operating.

Regardless of the labels used, these are all generally considered criminal offenses.

People often group these acronyms together and refer to them informally as DUIs and/or DWIs. In the discussion that follows, we’ll do the same when the distinctions are inconsequential.

State Laws

Each state has three main types of laws that address these violations. They are:

• Per se laws: Illegalize driving/operating with more than the legal limit for alcohol (and drugs in some states), regardless of impairment
• Impairment-based laws: Prohibit driving/operating while noticeably impaired, regardless of substance levels
• Zero-tolerance laws: Allow charges for underage drinking and driving/operating for minors who have any measurable amount of alcohol in their system

Prosecutors often bring charges under more than one type of law. For example, an adult with a BAC above the legal limit who also shows signs of impairment may be charged under the state’s per se and impairment-based laws.

How Do Police Officers Determine Impairment?

Arrests for these types of driving charges typically begin with a traffic stop. Before pulling someone over, law enforcement may observe signs of impairment.

Initial signs of impaired driving might include:

• Erratic driving
• Ignoring traffic signals
• Swerving/drifting between lanes

At the traffic stop, officers may also administer field sobriety tests or a breathalyzer (breath test to estimate blood alcohol content). If their suspicions are confirmed, they may arrest the driver.

Law enforcement must have reasonable suspicion to stop you and probable cause to arrest you.

Driving Privileges After Arrest

In some states, the departments of motor vehicles (DMV) or equivalent agencies can impose license suspensions immediately after arrest. This is distinct from the criminal court process.

For example, a driver arrested for driving under the influence may automatically get an administrative license suspension in Illinois even without a DUI conviction. State DMVs tend to impose this suspension if the driver fails or refuses a chemical test (such as a breath, urine, or blood test) after a lawful arrest.

DWI/DUI Penalties

Most states impose similar categories of penalties for convictions of these impaired driving/operating offenses. First offenses typically get lighter penalties if no aggravating factors were present.

Regardless of the label for the charges, penalties often include:

• Fines
• Driver’s license suspension/license revocation
• Jail time (especially for repeat offenses or high BAC levels)
• Probation
• Community service
• Ignition interlock device

As a practical matter, a DUI/DWI conviction can also affect job opportunities, raise car insurance rates, and stay on someone’s criminal record.

Do DWI/DUI Arrests Always Mean Convictions?

No. While a DUI/DWI arrest can be scary, it doesn’t always lead to a conviction.

Some states offer first-time offense programs that allow dismissal of charges after meeting certain conditions and completing treatment or education programs.

Additionally, an experienced DWI/DUI lawyer might be able to help you assert one or more legal defenses against the charges, which could include:

• Lack of impairment
• Lawful use of medication
• Unlawful traffic stop
• Lack of probable cause for arrest
• Improper testing/procedures

The court may also dismiss the charges if it finds the evidence inadmissible or insufficient.

If the charges were dismissed or you were found not guilty, you may be able to seal or expunge the record, depending on your state’s laws. This means the case is removed from the public record, so it’s generally an extremely appealing option if you’re eligible. However, not all states allow expungement and sealing of DUI/DWI records.

A DUI or criminal defense attorney in the state charging you is best suited to identify the most effective defense(s) for your DUI/DWI case.

Legal Help for a DUI/DWI/OUI

If you’re facing impaired driving/operating charges under any acronym, take a breath.

Your first step should be to identify a qualified DUI or criminal defense lawyer who can effectively advocate for you. You’ll want to share the details of your situation with them confidentially. They can help you understand your options, including eligibility for expungement. Under many circumstances, your attorney will try to negotiate a plea deal for reduced charges/penalties.

Jumpstart the process using FindLaw’s directory of DUI/DWI lawyers or criminal defense attorneys. To view ratings, background, and other information for area experts, click on the state bringing the charges against you. You can also narrow your search results by city for local options.

Get the help of a trusted advisor who can help you make informed decisions. They just might be your most important ally as you move forward.