Drunk driving (Drink driving in the UK and Australia) is the act of driving a motor vehicle (car, truck, etc.) while under the effects of alcohol. Drunk driving is illegal in most areas of the world. In some places, driving a motorless vehicle such as a bicycle while drunk is also illegal.
Most areas that make laws (jurisdictions) started with DWI (driving while intoxicated) laws, banning just alcohol. Later, most changed them to DUI (driving under the influence) laws, adding other drugs to those banned while driving. The most common blood alcohol content (BAC) limit in the United States is 0.08% for the legal meaning of drunk. Only three states still use the more lax, original standard of 0.10%. Many jurisdictions add extra penalties (more jail time and/or a longer DUI program) in cases where the driver's BAC is over 0.20%.
United States laws change
The first place in the United States to adopt laws against drunk driving was the state of New York in 1910, with California (1911) and others doing the same later. Early laws simply banned driving while drunk, with no mention of what BAC was banned (which means how drunk the person is). The state of Georgia was one of the last states to make laws against drunk driving. One of the years with the most alcohol related crashes was 1982. The year 1982 had 26,173 alcohol related deaths due to drunk driving.
In the US, most of the laws were greatly tightened in the early 1980s, largely due to pressure from groups like Mothers Against Drunk Drivers (MADD) and Young Adults Educating Responsible Drinking.