Louisiana calls impaired-driving offenses “DWI,” although many people search for them as DUI. The rules cover drivers who are impaired by alcohol, drugs, or a combination of substances, as well as drivers who meet specific blood alcohol concentration (BAC) limits. Understanding Louisiana’s BAC thresholds, criminal penalties, and separate driver’s-license procedures can help explain what may follow an arrest or conviction.
What Counts as DUI or DWI in Louisiana?
Louisiana’s principal impaired-driving law is Louisiana Revised Statute 14:98. It prohibits operating a vehicle while impaired by alcohol or drugs and also prohibits operating with a BAC at or above the limit that applies to the driver. The law applies to motor vehicles, not just passenger cars.
“DUI” is a familiar general term, but Louisiana statutes and courts usually use “DWI,” short for driving while intoxicated. A driver can face a DWI charge even without a BAC reading above the legal limit if the state alleges that alcohol, drugs, or another substance impaired the driver’s ability to operate safely.
Alcohol is not the only substance covered. Louisiana law can apply when a driver is impaired by a controlled dangerous substance, a medication, or a combination of substances. A valid prescription does not automatically make driving while impaired lawful. Drug-related cases may rely on officer observations, statements, field tests, toxicology evidence, or other circumstances rather than a single alcohol-style BAC threshold.
Louisiana BAC Limits by Driver Type
The applicable BAC limit depends on the driver’s age and the kind of vehicle being operated. BAC is typically expressed as grams of alcohol per 100 milliliters of blood or grams per 210 liters of breath.
| Driver category | Common BAC threshold | What it means |
|---|---|---|
| Most drivers age 21 and older | 0.08% | A driver at or above this limit can be charged under the per se alcohol provision. |
| Commercial motor vehicle drivers | 0.04% | A lower federal and state threshold applies while operating a commercial vehicle. |
| Drivers under age 21 | 0.02% | Louisiana’s underage zero-tolerance rule sets a much lower threshold. |
These limits are not permission to drive after drinking up to a particular amount. Impairment varies with factors such as body size, food, alcohol strength, medication, fatigue, and the time over which drinks were consumed. A driver may be impaired below the listed threshold, and a person’s BAC may continue to rise after driving stops.
For drivers under 21, Louisiana’s underage operating-while-intoxicated law generally makes it unlawful to operate a vehicle with a BAC of 0.02% or more. The rule is commonly described as “zero tolerance,” but the statutory threshold is not literally zero. Separate consequences may apply to the driver’s license, and the outcome can depend on the facts and the driver’s record.
Commercial drivers face additional consequences beyond a standard DWI case. A commercial driver’s license (CDL) can be disqualified for alcohol-related violations, including conduct that occurs while driving a personal vehicle in some circumstances. Federal rules generally prohibit operating a commercial motor vehicle with a BAC of 0.04% or more. CDL holders should check the applicable federal and Louisiana rules because a disqualification can affect employment even when the driver is not convicted of a standard DWI.
How Louisiana Determines Impairment
Police may investigate suspected impaired driving after observing unsafe driving, responding to a crash, or receiving a report. An officer may ask a driver to perform field sobriety tests and may seek a breath, blood, or urine sample. Field sobriety tests are not the same as a chemical test and do not directly measure BAC.
Breath and blood test results can be important evidence, but a result is not the only issue in a DWI case. The circumstances of the stop, the collection and handling of a sample, the testing equipment, timing, and compliance with required procedures may matter. A test result also does not, by itself, answer every question about whether the state can prove the charge.
Louisiana’s implied-consent rules generally apply to drivers who operate vehicles on state roads. By driving, a person is treated as having consented to specified chemical testing under the circumstances set out in law. Refusing a test can trigger an administrative license consequence and may affect the criminal case. A refusal does not mean that a driver is automatically convicted, but it is not a way to guarantee that no evidence will be used.
Criminal DWI Penalties in Louisiana
Criminal penalties depend on the number and timing of prior offenses, the charge, and any aggravating facts. The figures below summarize the general statutory ranges for adult DWI convictions under Louisiana law. They are not a prediction of a particular sentence; sentencing rules and eligibility for suspension or alternative treatment can be complex.
| Offense level | General statutory exposure | Other possible requirements |
|---|---|---|
| First offense | Fine of $300 to $1,000 and imprisonment of 10 days to 6 months | Probation conditions, substance-use evaluation or treatment, community service, and possible ignition interlock requirements |
| Second offense | Fine of $750 to $1,000 and imprisonment of 30 days to 6 months | Mandatory custody provisions may apply; treatment, probation conditions, and an ignition interlock may also be ordered |
| Third offense | Fine of $2,000 and imprisonment of 1 to 5 years | Enhanced custody and treatment provisions may apply; the case may be treated as a felony |
| Fourth or subsequent offense | Fine of $5,000 and imprisonment of 10 to 30 years | Significant mandatory imprisonment and other restrictions may apply |
Louisiana law contains detailed rules about which portions of a sentence may be suspended, when imprisonment is mandatory, and what conditions can be imposed. The exact result depends on the current statute, the prior-conviction history, and the case’s circumstances. A table of broad ranges cannot capture all sentencing rules, so the statutory text and qualified legal advice are important in an individual case.
Prior convictions can have consequences beyond the original court sentence. A later charge may be enhanced if earlier qualifying DWI convictions fall within the period specified by law. The dates, jurisdiction, and legal status of prior cases can matter when determining whether they count. An arrest is not itself a conviction, but unresolved cases may still create practical complications.
Additional penalties may arise when a DWI involves a crash, injury, death, a child passenger, a very high BAC, or other aggravating circumstances. A crash can lead to separate charges or civil claims in addition to DWI penalties. If a person is injured or killed, the potential criminal consequences can be substantially more serious than those listed for a basic first offense.
License Suspension, Refusal, and Administrative Procedures
A DWI arrest can start a driver’s-license process separate from the criminal prosecution. The Louisiana Office of Motor Vehicles (OMV) may take action based on a chemical-test result or a refusal, even before a criminal case is resolved. An administrative suspension is not the same as a court-ordered penalty, and the two processes can proceed on different schedules.
For an adult driver, a failed chemical test and a test refusal can lead to different suspension periods. Common statutory consequences include a 90-day suspension for a first test failure and a one-year suspension for a first refusal, with longer periods generally possible for repeat events. The applicable period can depend on prior history, the type of license, and the precise circumstances. Underage and commercial drivers may face additional or different licensing consequences.
Arrest paperwork or an OMV notice should be read promptly. A driver may have a limited time to request an administrative hearing or take other steps to challenge a proposed suspension. Missing a deadline can limit options, so the notice and current OMV instructions are more reliable than assuming a particular deadline applies to every case.
Some drivers may be eligible to seek a restricted license or driving privileges under conditions set by law. Eligibility can depend on the offense, the driver’s record, completion of required steps, and installation of an ignition interlock device. An interlock device measures alcohol in a driver’s breath and prevents the vehicle from starting if the result exceeds its programmed limit. It is not a substitute for court or OMV requirements.
Driving while a license is suspended can create a separate legal problem. Before driving, a person should confirm the license status and any restrictions directly with the OMV. A restricted license may authorize only specified driving, and violating its terms can jeopardize the privilege and lead to further penalties.
What Happens After a DWI Arrest?
After an arrest, the driver may receive a court date, paperwork related to the license, or both. The criminal case addresses the charge and possible sentence. The administrative process addresses driving privileges. These processes are related, but resolving one does not necessarily resolve the other.
Evidence in a case may include the reason for the traffic stop, an officer’s observations, field sobriety test results, chemical-test records, video, witness accounts, and statements. Relevant legal questions can include whether the stop and arrest were lawful, whether testing procedures were followed, and whether the evidence supports the specific charge. The answer depends on the record in the individual case.
Practical steps can include keeping all paperwork, noting hearing and court dates, arranging reliable transportation, and avoiding driving unless the license is confirmed valid. A person facing a charge can consult a Louisiana attorney familiar with DWI and license proceedings. Legal advice is especially important when a driver has prior convictions, holds a CDL, is under 21, or a crash caused injuries.
Where to Check Current Louisiana DWI Rules
Statutes and administrative procedures can change, and the outcome of a case depends on more than the general rules summarized here. The primary sources include Louisiana Revised Statutes 14:98 for DWI, 14:98.1 through 14:98.4 for offense-specific penalties, and the state’s implied-consent provisions. The Louisiana OMV website provides driver’s-license and administrative information.
For current legal text, use the official Louisiana Legislature law search and confirm that the version applies to the date of the alleged offense. This article provides general information, not legal advice. A Louisiana attorney can assess how current law applies to a specific arrest, test result, license notice, or prior record.