Laws

All states in the U.S. designate a per se blood or breath alcohol level as the threshold point for an independent criminal offense. A second criminal offense of driving "under the influence" or "while impaired" is also usually charged in most states, with a permissive presumption of guilt where the person's blood alcohol concentration (BAC) is .08 percent or greater (units of milligrams per deciliter, representing 8 g of alcohol in 10 liters of blood).See, e.g., New York Penal Law section 1192, found at New York State Assembly web site , go to "Bill Search and Legislative Materials", then "New York State Laws." Accessed April 2, 2008. Some states (e.g., Colorado) include a lesser charge, sometimes referred to as driving while ability impaired (this may apply to individuals with a .05 percent or above, but less than the .08 per se limit for the more serious charge.

The amount of alcohol intake to reach 0.08 percent varies substantially with body composition and health state. Risk of traffic accidents are increased already by far less dosage.

Prior to increased emphasis on drinking and driving in the 1980s, standards of .10-.15 percent were in place. The legal limit for commercial drivers in the U.S. is set at 0.04 percent. All states also observe a much stricter standard for drivers under the age of 21, commonly of .01-.02; these are often referred to as "Zero Tolerance" laws.

Driving under the influence of drugs

Unlike DUI, DWI, or OWUI cases that involve alcohol, there is generally no "per se" or legal limit that is employed for persons accused of driving under the influence of prescription medication or illicit drugs (although this is not the case in Ohio.) Instead, the key inquiry focuses on whether the driver's faculties were impaired by the substance that was consumed. The detection and successful prosecution of drivers impaired by prescription medication or illegal drugs can therefore be difficult. Similarly, although urinalysis toxicology screens can detect the presence of such substances in the driver's bloodstream, these analyses are unable to demonstrate that the substance was actually causing impairment at the time of driving. In response to these problems, several jurisdictions are currently considering legislation that would establish "zero tolerance" laws for those drivers arrested for DUI and found to have drugs or medication in their system. Additionally, breathalyzers have been developed for the purpose of administering roadside or laboratory tests that can detect the actual level of a controlled substance in an individual's body.

Penalties

Many jurisdictions require more serious penalties (such as jail time, larger fines, longer DUI program, the installation of ignition interlock devices) in cases where the driver's BAC is over 0.20, or 0.15 in some places. These additional sanctions are an attempt to deter and punish the operation of a vehicle at extremely high BAC levels and the concomitant danger posed to the safety of persons and property by heavily impaired drivers. In many cases, the reason given for these additional sanctions is because an average person would have passed out from that much alcohol. To be able to drive at that level, a person has to have consumed alcohol regularly for months in order to increase his/her alcohol tolerance and therefore is likely to have driven drunk repeatedly. However, since there is currently no standard test to measure alcohol tolerance, proponents of additional penalties for high-BAC offenders point to some studies that indicate that high-BAC offenders are more likely to be involved in a crash and more likely to recidivate. Critics of such laws point out that due to wide variations of alcohol tolerance, people with high tolerances will suffer the additional penalties, despite being less impaired than those with lower tolerances who drive with much lower BACs.

Some U.S. states also increase the penalties for drunk driving (even to the point of making it a felony) if certain other aggravating circumstances besides a high BAC are present, such as if the drunk driver caused an accident requiring the hospitalization of another person lasting greater than a specified period of time (often 72 hours), in cases where an accident resulted in property damage exceeding a certain amount (often $500), or where the driver has prior (and relatively recent) convictions for drunk driving. In addition, most states observe administrative laws that further penalize people convicted of DUI, typically enforced by the department that issues driver's licenses, usually titled Department of Motor Vehicles (DMV), or Department of Licensing. Australia and the UK have higher alcohol consumption rates, lower ages for alcohol consumption, much lower sentencing regimes for DUI Manslaughter, and much lower incidences of DUI.

DUI plates

In 1967, Ohio began to issue special license plates to DUI offenders who are granted limited driving privileges such as work-related driving until a court can rule that they can have full privileges back. However, judges rarely enforced the plates, so in 2004, the plates became mandated by state law to all DUI offenders.http://www.ohio-dui.com/changesJan1.htm Unlike Ohio's standard-issue plates (which as of 2008 are red and blue on white), the DUI plates are yellow with red writing with no registration stickers or graphics. They are sometimes known as "party plates."http://www.ohiocrimelawyer.com/dui_defense/dui_defense_restricted_plates.htmlhttp://radiogirlradiogirl.blogspot.com/2007/06/party-plates.html

Flying while drunk and related laws

Federal Air Regulation 91.17 (14 CFR 91.17) prohibits pilots from flying aircraft with an alcohol level of 0.04% or more, and/or within eight hours of consuming alcohol, and/or while under the impairing influence of any drug. 14 CFR 91.17 Federal Air Regulation 91.17 The same prohibition applies to any other crewmembers on duty aboard the aircraft (flight attendants, etc.). Some airlines impose additional restrictions, and many pilots also impose stricter standards upon themselves. Commercial pilots found to be in violation of regulations are typically fired or resign voluntarily, and they may lose their pilot certificates and/or be subject to criminal prosecution under Federal or State laws, effectively ending their careers.

Similar laws apply to other activities involving transportation; Michigan prohibits intoxicated bicycling, horseback riding, buggy driving, use of motorized farm implements, or boating, the latter whether a pilot or passenger, with much the same threshold of intoxication.