Alcohol Impairment

Alcohol is a depressant because it slows down the functions of the central nervous system. This means that normal brain function is delayed, and a person is unable to function normally. Alcohol affects a person’s information-processing skills, also known as cognitive skills, and hand-eye coordination, also referred to as psychomotor skills.

Consuming alcohol prior to driving greatly increases the risk of car accidents, highway injuries, and vehicular deaths. The greater the amount of alcohol consumed, the more likely a person is to be involved in an accident. In 2006, approximately 17, 600 people died in traffic crashes involving alcohol. In that same year, over 1.46 million drivers were arrested for driving under the influence of alcohol or drugs.

Some legal consequences of driving under the influence include:

  • Revoking the driver’s license (the most effective way of reducing drunk driving)
  • Jail sentences
  • Impounding or confiscating of license plates
  • Vehicle impoundment or immobilization

Repeat offenders sometimes have an interlock device installed in their vehicle that measures the driver’s BAC and prevents him or her from starting a car if intoxicated.

The severity of alcohol-induced impairment depends on the amount of alcohol present in the bloodstream, which is based on a person’s blood alcohol content (BAC) percentage. Most people begin to feel the effects of alcohol when their BAC ranges between 0.03% and 0.059%. At this point, the person feels mild euphoria, relaxation, and talkativeness, but he or she suffers from impaired alertness, judgment, coordination, and concentration.

A BAC of 0.06% to 0.10% results in blunted feelings, lack of inhibition, extroversion, and sexual pleasure. An individual’s reflexes, reasoning, depth perception, and vision are affected as well.

Between 0.11% and 0.20%, a person experiences over-expression, mood swings, and acts in a loud or disruptive manner. In addition, a person may suffer a decrease in reaction time and motor control along with staggering and slurred speech.

At 0.21% to 0.29%, the effects of alcohol induce stupor, loss of understanding, impaired sensations, possible loss of consciousness, and memory blackout.

Once BAC reaches at least 0.30%, a person risks experiencing severe depression, unconsciousness, and even death. Bladder function, breathing, and heart rate are all seriously impaired by this BAC level.

When an individual’s blood alcohol content reaches between 0.03% and 0.059%, the brain’s ability to handle tasks required for safe driving becomes impaired and more severely hindered as the BAC level increases. The brain’s ability to control eye movements and process information is affected simultaneously. This means that alcohol-impaired drivers take more time to read signs or respond to traffic signals or other drivers. At this BAC level, steering is affected in combination with the driver’s ability to stay in the proper lane.

Alcohol-impaired drivers also have difficulty concentrating on multiple tasks at a time. For example, a driver may be able to stay within the boundaries of a lane but forget to monitor his or her speed.