Drunk driving

Drunk driving (or drink-driving in British English) is the act of driving under the influence of alcohol. A small increase in the blood alcohol content increases the relative risk of a motor vehicle crash. In the United States, alcohol is involved in 30% of all traffic fatalities. Short-term effects of alcohol consumption Alcohol has a very significant effect on the functions of the body which are vital to driving and being able to function. Alcohol is a depressant, which mainly affects the function of the brain. Alcohol first affects the most vital components of the brain and "when the brain cortex is released from its functions of integrating and control, processes related to judgment and behavior occur in a disorganized fashion and the proper operation of behavioral tasks becomes disrupted." Alcohol weakens a variety of skills that are necessary to perform everyday tasks. One of the main effects of alcohol is severely impairing a person's ability to shift attention from one thing to another, "without significantly impairing sensory motor functions." This indicates that people who are intoxicated are not able to properly shift their attention without affecting the senses. People that are intoxicated also have a much more narrow area of usable vision than people who are sober. The information the brain receives from the eyes "becomes disrupted if eyes must be turned to the side to detect stimuli, or if eyes must be moved quickly from one point to another." Several testing mechanisms are used to gauge a person's ability to drive, which indicate levels of intoxication. One of these is referred to as a tracking task, testing hand–eye coordination, in which "the task is to keep an object on a prescribed path by controlling its position through turning a steering wheel. Impairment of performance is seen at BACs of as little as 0.7 mg/mL (0.066%)." Another form of tests is a choice reaction task, which deals more primarily with cognitive function.