There have been many studies that attempt to correlate traffic accidents with alcohol use. For example, a 1978 study by the Department of Transportation found that five percent of drivers in accidents resulting in property damage were intoxicated. The same study found that 9-13 percent of drivers in injury accidents were intoxicated.
According to National Highway Traffic Safety Administration (NHTSA) data from 1998, the number of drivers or non-occupants (e.g., pedestrians) with a blood alcohol level of at least 0.10 rises to an astonishing 30 percent in auto accidents involving fatalities.
Though it cannot necessarily be proven that alcohol was the cause of these accidents, there was a clear relationship. The data and the correlations between alcohol and auto accidents led the Department of Transportation to what most of us would consider the obvious conclusion that "alcohol beyond a certain amount ... is associated with increased crash risk."