DUI-DWI Terms & Definitions

There are a number of common DUI and DWI law terms that can be helpful to someone who finds themselves arrested for drunk driving. Some of the DUI terms listed here refer to the arrest itself, while others have to do with the legal process that follows. If you need further clarification regarding DUI and DWI law definitions, your DUI attorney can help you better understand the terms that apply to your specific drunk driving case.

Absorption Rate: The rate at which consumed alcohol finds its way into the blood stream. While alcohol sits in the stomach, its absorption is delayed. Absorption rate will be affected by how much was eaten, individual biologic differences, and what type of beverage was consumed. When drinking continues over a course of hours, both absorption and “burnoff” (metabolizing of alcohol) will be happening simultaneously.

Administrative License Suspension: A law that allows the prompt suspension of the license of drivers charged with Driving While Intoxicated (DWI) when a driver has a BAC above the prescribed limit, or sometimes if a driver refuses to take a roadside blood or breath test. Thus the license may be suspended before adjudication of the DWI charge.

BAC: Short for “blood alcohol concentration.” BAC refers to the amount of alcohol in your bloodstream and is measured in percentages. BAC can be measured either by breath, blood or urine testing and is often used by law enforcement to determine whether or not a motorist is “legally drunk.” All 50 states have adopted BAC laws that make it illegal to drive with a BAC at or above a set amount. As of May of 2007, all 50 states have adopted 0.08% as the BAC limit.

Blood Test: A laboratory test that directly measures the percentage of alcohol content of the blood drawn from a DWI suspect.

Breath Test: A test of blood alcohol level that is derived from measuring the alcohol level of the suspect’s breath. It depends for its accuracy on the machine’s receiving air from deep in the lungs, and a mathematical formula is used to extrapolate the blood alcohol level from the lung-air alcohol level.

Breathalyzer: A portable machine used by law enforcement to measure the BAC of suspected drunk drivers.

Burnoff Rate: The rate at which alcohol in the body is metabolized. During burnoff, the blood alcohol level drops, giving rise to the “falling curve” term to describe the graph of the decrease in BA.

Chemical Test: As it relates to DUI, a test of the alcohol or drug concentration in a person's blood. A Breathalyzer, blood analysis, or urinalysis can be used as chemical tests for alcohol. If other drugs are suspected, a blood test or urine test is used.

Commercial Vehicle: A vehicle driven for business purposes. In the DUI context, these are the consequences for driving a commercial vehicle while drunk.

Community Service: Depending on the offense, your state may offer community service as a way to work off fines or jail time, which means you are living at home and reporting during the day to pick up trash, sweep public buildings, assist community charitable or public oriented organizations, or perform other services to the community. Community service may also be a mandatory part of your sentencing.

Conditional License: A conditional license is a license granted “on condition” of something, such as completing a DUI course or alcohol treatment program. Once that “condition” has been met, a standard license is generally issued or reinstated.

Diversion: A court program that can suspend the prosecution of a criminal DWI charge in exchange for performing certain tasks, such as attending a drinking driver program. At the end of the period of successful diversion the charges are dismissed. This is less frequently used in DWI cases these days, but still exists in some states.

Driver Responsibility Tax: Some states charge those convicted of a DUI with an extra tax on top of fines and court costs. This usually consists of a tax that is payable to the state for three years after the incident occurred (e.g.: $250 per year for three years). In most cases, failure to pay the yearly assessment on time results in license suspension.

DUI School: DUI schools are typically drug and alcohol education programs designed to help you realize how dangerous drinking and driving is and to hopefully ensure you are not a repeat offender. Your state will likely have a list of approved schools for you to choose from.

DUI: Driving While Under the Influence. Just a different way of stating DWI.

DWI: Driving While Intoxicated. Just a different way of stating DUI.

Felony: A serious crime, such as murder, rape or burglary, for which there is a stricter sentence given than for a misdemeanor. Felonies are usually categorized by degrees. 1st degree felonies are the most serious class (with the highest fines and penalties), 2nd degree felonies are less serious, and so on. Many states treat DUIs that cause serious bodily injury as a 3rd degree felony. If there has been a death as a result of the DUI, it might be classified as a 1st or 2nd degree felony, depending upon the prosecutor and the situation. Some states elevate DWI to felony status even without an injury or death, if the suspect has a given number of prior DWI convictions. A felony can result in a sentence to state prison instead of county jail.

FST: Field Sobriety Test. A series of physical and mental coordination tests designed to help an officer decide if a driver is DWI. These may include walking the straight line, reciting the alphabet, standing still with feet together and arms extended, standing on one foot, etc. These are highly subjective, but if the officer concludes the driver was DWI, he will require a BA test. States seldom have statutes that penalize refusing to perform FST’s, but most will penalize refusal to take a Blood Alcohol Test with license suspension or other penalties.

High BAC: Threshold blood alcohol content for which maximum penalties and fines may apply, even on a first offense.

Ignition Interlock Device: An ignition interlock device is an in-car alcohol breath screening device that prevents a vehicle from starting if it detects a blood alcohol concentration (BAC) over a pre-set limit of .02 (i.e., 20 mg of alcohol per 100 ml of blood). The device is located inside the vehicle, near the driver’s seat, and is connected to the engine's ignition system. Many states require that the device be used by those convicted of DUI.

Implied Consent Laws: Some states have implied consent laws. If you have a driver’s license in one of these states, you have, by implication, consented to have your blood alcohol concentration measured. In many states, you may refuse to take the test, but fines and license suspensions may be the result. In some states, an officer may not pull over drivers randomly to test them, but must have “probable cause” to believe the driver is DWI before pulling them over (such as observing “weaving”).

Intoxilyzer: A brand name for a blood alcohol breath testing machine.

License Revocation: A license revocation means your driving privileges have been cancelled. You will likely need to reapply for a driver's license after a designated length of time.

License Suspension: A license suspension means you may not drive for the period of your suspension. Driving privileges are typically administered by a state agency other than the court system. It could be the Secretary of State, the Department of Motor Vehicles or another agency. If your license is suspended, the suspension will likely take effect immediately upon arrest, and not upon conviction. Check your state’s laws. You, or your lawyer on your behalf, may be able to negotiate a limited suspension, meaning you may drive to and from work, but nowhere else.

Miranda Rights: The formal advisement that you have the right to remain silent and to have a lawyer present before answering questions, which police must recite prior to questioning someone who is in custody. Seldom relevant to DWI cases, because the police never arrest anyone until after questioning (Have you been drinking?), after the FSTs, and maybe even after the Blood Alcohol Testing. Of course, one does have the right not to answer questions like that one, or “How much have you had to drink? When?”, but no officer will advise you of that.

Misdemeanor: A crime less serious than a felony. Misdemeanors are sometimes categorized by degrees. 1st degree misdemeanors are the most serious class (with the highest fines and penalties), 2nd degree misdemeanors are less serious, and so on. Many states treat a first DUI conviction as a misdemeanor.

Open Container Laws: In some states, it is illegal to have an open container of alcohol in your vehicle. Many states have laws that make it illegal for drivers and passengers to have open containers in the vehicle.

Probation: When all or part of the required jail time is suspended in exchange for good behavior, as determined by checking in with a probation officer. Jail time may be reinstated if it is found the terms of probation are being violated. Some grants of probation are unsupervised, but a violation may be found after a new arrest.

Provisional (or Restricted) License: AA provisional license typically withholds certain license privileges. In a DUI context, a provisional license might be granted to someone to drive to and from work only, or to and from the court ordered drinking driver program.

Regurgitation: Ejecting some stomach contents up into the throat or mouth. With alcohol in the stomach, this can fool a Breathalyzer into thinking that the blood alcohol level is much higher than it is. Officers administering a breath test are supposed to watch the suspect to see he does not burp or regurgitate prior to the test. A cloud of alcohol burped up into the mouth will invalidate the breath test results.

Rising Curve Defense: A defense to DWI based upon the claim that the driver was not under the influence and did not have .08% blood alcohol when he or she was driving, but that it rose to that level after arrest due to the fact that alcohol was still being absorbed. Consequently, a long delay between being pulled over and having a BA test helps the suspect in many cases.

Sobriety Checkpoints: A system where law enforcement agencies select a particular location for a particular time period and systematically stop vehicles (for example, every third car) to investigate drivers for possible DWI. If any evidence of intoxication is noted, a detailed investigation ensues.

Urine Test: A laboratory chemical test of the suspect’s urine to determine the suspect’s blood alcohol level. Can be inaccurate because of the mixing of higher alcohol level urine from earlier with lower alcohol level urine closer to the driver’s being pulled over. Can give an artificially high reading for that reason.

Vehicle Impound or Vehicle Immobilization: Vehicle impound is an option used by some states when there has been more than one DUI conviction. The vehicle may be seized, or an ignition interlock device may be installed on the steering wheel of the car, requiring the driver to pass a breath test using the device before he or she can start the vehicle and drive away.

Zero Tolerance BAC: Allowable blood alcohol content for minors (as defined by the state). This percentage can be as low as 0% (meaning no alcohol content may be detected-hence the term “zero tolerance.”) or as high as 0.02%.