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Driving under the influence of alcohol, drunk driving, drinking and driving, or drink-driving, is the act of operating a motor vehicle (and sometimes a bicycle or similar human-powered vehicle) after having consumed alcohol (ethanol) or other drugs, to the degree that mental and motor skills are impaired.
In addition to driving under the influence of alcohol and driving under the influence of other drugs, a third "DUI" offense consists of driving under the combined influence of alcohol and other drugs. The drugs causing or contributing to the impairment need not be illegal, but can consist of lawfully prescribed or over-the-counter medication. Anti-drunk-driving advertising campaigns have aimed to raise awareness of the legal situation and the dangers of driving while intoxicated. Drunk-driving is responsible for a large number of deaths, injuries, damage and accidents every year.
The specific criminal offense may be called, depending on the jurisdiction, driving while intoxicated (DWI), driving while impaired (also DWI), operating while intoxicated (OWI), operating a motor vehicle while intoxicated (OMVI), driving under the influence [of alcohol or other drugs] (DUI), driving under the combined influence of alcohol and/or other drugs, driving under the influence per se or drunk in charge [of a vehicle]. Such laws may also apply to boating (as in Canada's Ontario province[2]), piloting aircraft, and even bicycling in some states such as California.
BAC is most conveniently measured as a simple percent of alcohol in the blood by weight. It does not depend on any units of measurement. In Europe it is usually expressed as milligrams of alcohol per 100 millilitres of blood. However, 100 milliliters of blood weighs essentially the same as 100 milliliters of water, which weighs precisely 100 grams. Thus, for all practical purposes, this is the same as the simple dimensionless BAC measured as a percent. Since 2002 it has been illegal in all 50 US states to drive with a BAC that is 0.08% or higher.
Driving while consuming alcohol is generally illegal, though driving after drinking remains legal. In some jurisdictions it is also illegal for an open container of an alcoholic beverage to be in the passenger compartment of a motor vehicle or in some specific area of that compartment.
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Blood alcohol concentration (BAC) is the amount of alcohol in an individual’s body, measured by the weight of the alcohol in a volume of blood. The BAC limit determines the maximum amount of alcohol that can be consumed before it is illegal to operate a motor vehicle on a public road.
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Drunk Driving - The Dangers
Although alcohol-related traffic fatalities have been on the decline in recent years, the certainty of highway deaths due to alcohol impaired drivers is so predictable each holiday period many state highway patrol departments each year issue highway fatality "projections" that will turn out to be uncanningly accurate.
In spite of all the warnings, public awareness and educational programs, stiffer penalties for violations, and efforts by law enforcement agencies across the nation to be more visible and diligent in protecting the highways, people will still make the decision to get behind the wheel of their vehicles while intoxicated.
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http://www.indiana.edu/~iupd/drunkdriving.htm
http://www.maddorangecounty.org/impact.htm
http://alcoholism.about.com/od/dui/a/impaired.htm
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