Some states now have two statutory offenses. The first is the traditional offense, variously called driving under the influence of alcohol (DUI), driving while intoxicated/impaired (DWI) or operating while intoxicated/impaired (OWI). The second and more recent is the so-called illegal per se offense of driving with a blood-alcohol concentration (BAC) of 0.08% (previously 0.10%) or higher. The first offense requires proof of intoxication, although evidence of BAC is admissible as rebuttably presumptive evidence of that intoxication; the second requires only proof of BAC at the time of being in physical control of a motor vehicle. An accused may be convicted of both offenses, but may only be punished for one.
It is also a criminal offense in all states to drive a vehicle while under the influence of drugs DUID, or under the combined influence of alcohol and drugs; the drugs themselves need not be illegal, but can be prescription or even over-the-counter. In some states, the effects of some herbal remedies (such as Kava Kava extract) fall into this category. This offense requires evidence of impairment as a result of the drugs or drugs and alcohol, although some states have passed laws making driving with the mere presence of certain drugs a criminal offense. A number of states have expanded upon DUI laws to make operating a motor vehicle while impaired a punishable offense, which includes sleep deprived driving, among other things.
Some states also include a lesser charge of driving with a BAC of 0.05%; other states limit this offense to drivers under the age of 21. All states also now have zero tolerance laws: the license of anyone under 21 driving with a BAC of .01% or higher (.02% in some states) will be suspended.
The blood-alcohol limit for commercial drivers is 0.04%. Commercial drivers are also subject to stricter punishments for exceeding the blood-alcohol limit.
Pilots of aircraft may not fly less than eight hours after consuming alcohol, while under the impairing influence of alcohol or any other drug, or while showing a blood alcohol concentration equal to or greater than 0.04 grams per decilitre of blood.
The various versions of "driving under the influence" generally constitute a misdemeanor (punishable by up to one year in jail). However, the offense may be elevated to a felony (punishable by a longer term in state prison) if the incident caused serious injury (felony DUI), death (vehicular manslaughter or vehicular homicide), or extensive property damage (a state specified dollar amount) or if the defendant has a designated number of prior DUI convictions within a given time period (commonly, 3 prior convictions within 7 years). California, which is being followed by a growing number of states, now charges second-degree murder where the legal state of mind of malice exists -- that is, where the defendant exhibited a reckless indifference to the lives of others.
Administrative License Suspension (ALS)
* Drivers stopped for drunk driving who refuse to take the sobriety test or whose test results exceed the legal limit of Blood Alcohol Concentration (BAC) may have their driver's license confiscated on the spot, and their suspension begins immediately (Florida).
* This is a common misconception. Florida Law clearly states (note bold portions):
316.1932 Any person who accepts the privilege extended by the laws of this state of operating a motor vehicle within this state is, by so operating such vehicle, deemed to have given his or her consent to submit to an approved chemical test or physical test including, but not limited to, an infrared light test of his or her breath for the purpose of determining the alcoholic content of his or her blood or breath if the person is lawfully arrested for any offense allegedly committed while the person was driving or was in actual physical control of a motor vehicle while under the influence of alcoholic beverages. The chemical or physical breath test must be incidental to a lawful arrest and administered at the request of a law enforcement officer who has reasonable cause to believe such person was driving or was in actual physical control of the motor vehicle within this state while under the influence of alcoholic beverages.
* Law enforcement officers conduct Field Sobriety Tests (FSTs), including the use of portable breath analyzers (PBAs) for the purposes of determining if probable cause exists for an arrest. Until an arrest has been made, a motorist is under no obligation to perform any test. Most states consider such a pre-arrest refusal inadmissible in court.
* Depending on previous offenses or refusals, licenses may be automatically suspended for a period of 90 days to five years, or permanently revoked for multiple DWI convictions (Connecticut).
* As of 2005, only nine states did not have ALS laws: Kentucky, Michigan, Montana, New Jersey, New York, Pennsylvania, Rhode Island, South Dakota and Tennessee.
An SR-22 is an official documentation required to redeem a suspended drivers license and get a car registered at the local Department of Motor Vehicles (DMV). A SR22 Filing is a form issued by an insurance company which removes a suspension order placed by the DMV's office on an individual's driving privilege. The most common reason for an SR22 filing is an arrest for Driving Under Intoxication (DUI) or Driving While Intoxicated (DWI). The filing provides a guarantee to the state that an insurance company has issued at least minimum liability coverage for the person making that filing and that the insurance company will notify the DMV should the insurance ever lapse for any reason.