Alcohol compromises judgment. Any given night in any tavern will prove that point spectacularly. When it comes to chronic use and the disease of alcoholism, the judgment problem manifests itself as a complete level of denial of any problem. It's the only disease that convinces the patient he or she isn't sick. A person with cancer or the flu feels and knows he's sick. A person with alcoholism doesn't feel sick until he tries to quit.
When I do community presentations, I haul a couple of participants up to the stage to demonstrate that the mind works best on the equation, Intellect over Emotion, but alcohol inverts the equation to Emotion over Intellect. That's what causes ordinarily smart people to do extraordinarily dumb stuff. Like getting behind the wheel. Judgment is impaired first, but reaction time suffers with the very first drink, too. It doesn't matter how big or experienced the drinker is, impaired reaction time is a function of alcohol being a central nervous system depressant drug. Motor skills begin to diminish at .02 Blood Alcohol Concentration (BAC). The legal limit for driving is .08 BAC in the U.S.
The Oxford Journal demonstrated in a lab with a stopwatch what most drinkers deny with a vengeance. Inspection Time – the time interval between seeing something and accurately processing it – was measurably slower at even .05 intoxication. The drug narrows the field of vision, cuts color visibility, increases problems with glare and and difficulty moving from light to dark. Then reaction time – responding to what was seen – told the rest of the story of how poorly the central nervous system performs on the drug alcohol.
Reaction time is 1/5 of a second for an unimpaired driver. With alcohol in the system, reaction time is slowed to 4/5 of a second at .05 BAC. At 60 mph, a second means 88 feet. A fifth of a second is 17.5 feet, 4/5 of a second is 70.4 feet. The SUV slamming on the brakes in front of an impaired driver is 53 feet closer, reaction-time wise, compared to an unimpaired driver. It's math and science and has nothing to do with driving or drinking experience.
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