There are many types of driving offenses with varying penalties and consequences, but one of the most serious offenses is that of impaired driving. This criminal offense is known by various labels such as Driving Under the Influence (“DUI”), Driving While Intoxicated (“DWI”), and Operating Under the Influence (“OUI”), among others. The labels and acronyms are equivalent to the charge of drunk driving. Various substances, not just alcohol, can cause impairment, including illegal drugs, over-the-counter medications, and prescription medication.

Determining Impairment

A police officer may administer a field sobriety test to determine whether someone is driving while impaired. This test determines the ability of the person to perform basic functions, such as counting backwards or walking a straight line. The officer’s determination may also be based on an observance of the person’s demeanor, speech, alcohol odor emanating from the person, and eye movement.

A person’s blood-alcohol concentration can be determined at the scene of a vehicle stop through the use of breath analyzing equipment. Some drivers may also be subjected to hospital blood and urine tests to determine the level of alcohol and drugs in their system.

Most states consider persons having blood-alcohol concentration levels of .08% or higher to be impaired. All states have “implied consent” laws that require suspected impaired drivers to submit to testing. Failure to submit to testing can result in the suspension or revocation of driving privileges. If a person is convicted of impaired driving, a refusal to submit to testing may result in a greater fine or punishment.

The Impaired Driving Case

A person who is accused of driving while impaired may be charged with a felony or a misdemeanor. Examples of issues that may arise in an impaired driving case are:

  • whether the officer had probable cause (a legally sufficient reason) to stop the vehicle;
  • whether the person charged was actually driving the vehicle;
  • whether the blood alcohol level was above the legal limit at the time the person was driving;
  • whether the arresting officer followed the correct procedures for administering blood and urine tests;
  • whether the equipment measuring the blood and urine levels was properly maintained and calibrated;
  • whether blood and urine samples were properly preserved;
  • whether the officer read the driver his rights; and
  • whether any of the driver’s Constitutional rights were violated.

In determining punishment, some of the things a jury may consider is whether the defendant has been convicted of a similar crime before, whether defendant was driving recklessly, whether anyone was injured or killed, whether property was damaged, and whether the defendant was of legal drinking age.

Generally, an impaired driver may be convicted for the offense of driving impaired itself and for having blood alcohol concentration levels exceeding state limits. Many states have “zero-tolerance” laws that forbid people under the age of 21 from consuming any amount of alcohol and driving.


If convicted of driving while impaired, the consequences can include:

  • loss of driving privileges
  • fines
  • alcohol or substance abuse treatment
  • increased insurance premiums
  • community service requirements
  • installation of ignition interlock on impaired driver’s vehicle
  • imprisonment