DUI Offense Basics

In every state, it is a crime for a driver to operate a vehicle while impaired by the effects of alcohol or drugs.

The specific offense may be called driving under the influence (DUI), driving while intoxicated (DWI), operating under the influence (OUI), and even operating a motor vehicle intoxicated (OMVI).

Whatever the specific title, DUI laws make it unlawful for a person to operate a car, truck, motorcycle, or commercial vehicle if:

• The driver's ability to safely operate the vehicle is impaired by the effects of alcohol, illegal drugs, prescribed medications such as painkillers, or even over-the-counter medications such as antihistamines; or
• The driver is intoxicated at a level above established DUI standards, such as blood-alcohol concentration (BAC).

Field Sobriety and Chemical Tests

When a law enforcement officer makes a vehicle stop and suspects that the driver may be intoxicated, the officer will conduct a "field sobriety" test on the driver and may ask for his or her consent to some form of chemical test for intoxication.

Field sobriety tests usually involve a police officer asking a driver to perform a number of tasks that assess any impairment of the person's physical or cognitive ability. Examples of field sobriety tests include evaluating the driver's ability to walk a straight line, heel to toe, requiring the driver to maintain balance while standing on one leg; and looking for horizontal gaze nystagmus (HGN) in the eyes of the driver.

Chemical tests could also be conducted in connection with the vehicle stop, using a Breathalyzer that measures a driver's breath-alcohol concentration (BrAC) or taking a blood sample to be evaluated later at a lab for the purposes of evaluating blood-alcohol concentration (BAC). Many states do not allow a driver suspected of DUI to choose which type of chemical test is administered.

Refusing a Chemical Test: "Implied Consent" Laws

All states have "implied consent" laws (or "duty to submit" laws) that require vehicle drivers to submit to some form of chemical test, such as breath, blood, or urine testing, if suspected of DUI. The logic behind such laws is that, by assuming the privilege of driving a vehicle on state roads and highways, drivers have effectively given their consent to DUI testing when a police officer reasonably believes the driver is under the influence of alcohol or drugs.

If a driver refuses to submit to such testing, implied consent laws can be used to impose penalties such as mandatory suspension of a driver's license, usually for six months or more. Often, license sanctions for test refusal are harsher than those imposed after failure of a chemical test. In most states, a driver's refusal to submit to a chemical test may also be used to enhance the penalties imposed if they are eventually convicted for DUI.

A state-by-state listing of laws associated with DUI can be found here.

"Per Se" and "Zero Tolerance" DUI Laws

All states have DUI laws that deem "per se intoxicated" any driver with a blood-alcohol concentration (BAC) above a set limit (now 0.08 in 49 of 50 states). This means that drivers with a BAC at or above 0.08 are intoxicated in the eyes of the law, and no additional proof of driving impairment is necessary. In Utah, the law was changed in 2019 to define intoxication at 0.05 BAC, and legislators in other states are proposing similar changes in the wake of Utah's reduction in traffic fatalities.

All states also carry "zero tolerance" laws that target drivers under the legal drinking age. These laws penalize persons under 21 for operating a vehicle with any trace of alcohol in their systems (a BAC above 0.0), or with negligible BAC levels such as 0.01 or 0.02.

Keep in mind that a driver may still be arrested and convicted for DUI without proof of "per se" intoxication, when other evidence of impairment is shown. For example, a driver with a 0.06 BAC level can be found guilty of DUI if an arresting law enforcement officer testifies that he observed the driver's vehicle swerving badly, and that the driver exhibited both slurred speech and severe inattention during questioning after a vehicle stop.

DUI Convictions: Criminal Penalties

A DUI conviction may carry criminal penalties including fines, jail time, probation, and community service. Some state laws impose certain minimum penalties for first-time offenses, then designate increased penalties for each offense thereafter. The severity of criminal penalties will vary according to the circumstances of the offense, including:

• Whether the driver has a history of DUI violations;
• Whether the driver was operating a commercial vehicle at the time of the DUI;
• Whether the DUI violation occurred while there was a child in the vehicle;
• Whether the DUI violation occurred simultaneously with another dangerous moving violation, such as speeding or eluding the police;
• Whether the DUI violation involved a car accident in which property damage occurred;
• Whether the DUI violation involved a car accident in which another person was injured or killed; and
• Whether the driver was under the legal drinking age at the time of the DUI violation.

For a state-by-state listing of certain penalties associated with DUI, go here.

DUI Arrest and Conviction: Driving Privilege Penalties

In addition to potential criminal penalties, a DUI arrest or conviction will have an immediate negative impact on driving privileges.

Most state laws allow a motor vehicle department to immediately suspend the driver's license of any person operating a vehicle with a BAC above the state limit for intoxication, or any driver who refuses to submit to BAC testing. The driver's vehicle could also be confiscated or impounded, and the DUI offender will likely incur significant administrative costs. This loss of driving privileges can normally occur even before a DUI conviction.

Most states allow a DUI arrestee to obtain a temporary license and request an administrative hearing at which he or she may argue against license suspension, or for restoration of limited driving privileges.

As with criminal penalties, the impact of a DUI arrest or conviction on driving privileges will vary according to the driver's history of DUI violations and the severity of the offense. An increasingly popular DUI consequence, especially for repeat offenders, is mandatory installation of an "ignition interlock" device on the offender's vehicle. This breath-testing device measures the vehicle operator's BAC, and will prevent operation of the vehicle if more than a minimum amount of alcohol is detected.

Where this requirement is used, the DUI offender is typically required to pay costs of installation, rental, and maintenance of the ignition interlock device. Rental fees alone can amount to as much as four dollars per day, so a DUI offender's expenses can add up quickly when an ignition interlock device is required.

A state-by-state listing of certain penalties associated with DUI is available here.

Plea Bargains in DUI Cases

Due to recent law enforcement trends that focus on preventing DUI by penalizing offenders harshly, some district attorney offices refuse to negotiate plea bargains in DUI cases. This is especially true if evidence of the violation is strong. In fact, some states, like Kansas, have enacted laws that prohibit government attorneys from entering into plea bargains with DUI defendants. However, in other cases a DUI charge may be reduced to a lesser offense like reckless driving or an "open container" violation.

Questions About DUI Offenses? Talk to a Lawyer

While this article provides DUI offense basics, each case is unique. If you have been charged with a DUI, contact a local DUI attorney who can help you get a much better outcome for your case, whether it's a reduced charge, probation instead of jail time, or a solid defense leading to dropped charges or a "not guilty" verdict.