Drunk driving, sometimes called driving while intoxicated (DWI) or driving under the influence (DUI), can stem from two different scenarios under drunk driving laws: the first is when a driver has high blood-alcohol levels, and the second is when a driver is physically impaired by the use of a substance.
Driving with a blood alcohol level that is over the state’s maximum permissible blood alcohol limit is considered drunk driving. The limit for adults is 0.08% in all 50 states as of May, 2007. This is due to the fact that in October, 2000, Congress passed a law requiring all states to adopt limits of 0.08% by 2004 or lose some of their federal highway funds. Apart from the 0.08% limit, some states have zero tolerance limits for young drivers. Most European countries have limits that are far below 0.08%. You may be considered legally drunk even though you do not feel or look as though you are under the influence of alcohol.
You may also be guilty of DUI / DWI for driving when your physical abilities are impaired by drugs or a combination of drugs and alcohol. In the eyes of the law, it makes no difference whether the drug is legal or illegal, prescription or over-the-counter. If taking that drug impacts your senses of seeing, hearing, talking, walking, judging distances, or any other physical or mental ability used in driving, you may be found guilty of a drunk driving offense.
In 1997, according to the United States Department of Transportation, 38.6% of all traffic deaths were alcohol-related, with a total of 16,189 alcohol-related traffic deaths. Fifteen years earlier, in 1982, alcohol-related deaths represented 57.3% of that year's 43,945 total traffic fatalities. In addition, a study done by the National Highway Safety Administration reported that the risk of a driver with a 0.10% blood alcohol content (BAC) being in fatal accident is many times greater than a driver with a 0.08% BAC. Over the years, the excessive number of deaths and injuries from drunk driving-related accidents has called for more vigorous enforcement of preventative laws.
Despite the fact that drivers are legally drunk at 0.08%, the head of the Montana State Police stated that the average driver arrested for a DUI in Montana has a 0.17% BAC. Thus, most of those arrested for a DUI or DWI are way over the line and a hazard to themselves and other drivers on the road.