Alcohol-related traffic crashes are defined by the United States National Highway Traffic Safety Administration to include any and all vehicular (including bicycle and motorcycle) accidents in which any alcohol has been consumed, or believed to have been consumed, by the driver, a passenger or a pedestrian associated with the accident. Thus, if a person who has consumed alcohol and has stopped for a red light and is rear-ended by a completely sober but inattentive driver, the accident is listed as alcohol-related, although alcohol had nothing to do with causing the accident. Alcohol-related accidents are often mistakenly confused with alcohol-caused accidents.
Nationally, 12.8% of all drivers involved in fatal accidents during 2001 are known to have been intoxicated according to the blood alcohol concentration (BAC laws) of their state. This number is based on a systematic examination of the official records of each and every accident involving a fatality during that year in the US.
The higher number (about 40%) commonly reported in the press refers to accidents defined as alcohol-related as estimated (not measured) by the National Highway Traffic Safety Administration.
Regardless of disagreements and confusion regarding traffic accidents involving alcohol, they have declined dramatically over the past 25 years in the US.