Driving Under the Influence
Driving Under the Influence
Today we hear about “drunk Driving,” and driving while intoxicated.” Neither of these phrases are correct or accurate terminology.
The National Highway Traffic Safety Administration has requested that all traffic safety professionals, trainers, and states stop the common use of drunk or intoxicated driving. The rational for this request is the ambiguity of these terms. Ask ten different individuals for the definition of either being drunk or intoxicated, and you are likely to get ten different definitions.
This is why the NHTSA has asked that only the term “impaired” be used. Impairment is a better term to use as it can reflect the results of alcohol, legal and illegal drugs and even fatigue. It really does not matter why a driver is impaired; the fact is that they have chosen to operate a vehicle while their abilities are impaired.
Driving is demanding and it’s a task that requires both a driver’s mind and body to work effectively. Alcohol interferes with driving because it impairs the driver’s mental and physical abilities. Driving requires a driver’s undivided attention and alcohol interferes with a driver being able to multi-task things such as watching for other vehicles, roadway signs, and controlling the vehicle they are operating.
Judgment is the first important driving ability affected by alcohol. Judgment is what guides a driver’s behavior.
Judgment enables a driver to think clearly and make quick, responsible decisions. To drive safely, a driver must be able to judge speed, time and distance accurately. These things are all affected with the very first consumption of alcohol, and become markedly impaired as a person continues to consume alcohol.
A person whose judgment has been impaired by alcohol may drive too fast or too slow. They may follow too closely or pass without the proper clearance. The problem with the consumption of alcohol is the person may not be aware they are impaired. This is another result of impaired judgment. Some people even believe the myth that they drive better after consuming alcohol. Nothing could further from the truth.
Vision is the second factor affected by alcohol
A driver who has consumed alcohol may see the roadway and everything on it as blurred. They might even be seeing double images of vehicles and people.
About 90% of the information a driver needs to operate a motor vehicle effectively comes from visual sources. Alcohol will affect a driver’s vision without the driver even being aware of what’s happening. Alcohol’s effects on vision begin at low BAC levels. Even one standard drink can affect a person’s vision.
Alcohol has an effect on visual acuity. It causes eye muscles to relax so light isn’t directed to the eye properly. As a result, objects become unclear, blurry or fuzzy. Alcohol reduces the ability to see in low light situations and also affects our ability to recover from glare situations.
Alcohol diminishes a person’s Peripheral Vision which is the ability to see objects on either side of the head when looking straight ahead. In fact, at .05 BAC, a driver’s side vision is reduced by as much as 30%.
Depth perception is also affected. Alcohol causes each eye to get a slightly different picture. This impairs a driver’s ability to gauge distance and increases the chances of collisions.
Alcohol, being a depressant, can also affect emotions leading drivers to act in ways they might not normally act when sober.
They may take additional risks, or drive more aggressively. Alcohol has no positive effects for the operator of any motor vehicle.
Alcohol also affects a driver’s coordination skill. Alcohol slows down a driver’s reaction time by 15 to 25 percent. Alcohol consumption will cause a driver to take more time to respond to an immediate hazard.
BLOOD ALCOHOL CONCENTRATION (BAC)
BAC or Blood Alcohol Concentration is a weight of alcohol per volume of blood or breath.
The American Medical Association has defined the blood alcohol concentration of impairment for all people to be 0.04 grams/100 liters of blood (equivalent to .04 grams/210 liters of breath).
It is important to understand alcohol impairment begins long before a person reaches the level considered by Florida state statutes to be under the influence to the extent that a person’s normal faculties are impaired.
Some people believe that hard liquor will cause a person to become impaired quicker. In reality (see the graphic below) a 12 ounce can of beer, 5 to 6 ounces of wine and 1.5 ounces of 80 proof alcohol all have relatively the same amount of alcohol per volume.
12 ounces of 4% beer 0.48 ounces of absolute alcohol
5 ounces of 10% wine 0.50 ounces of absolute alcohol
1.25 ounces of 40% vodka (80 proof) 0.50 ounces of absolute alcohol
1.25 ounces of 43% whiskey (86 proof) 0.52 ounces of absolute alcohol
All of the above servings have approximately 0.50 ounces of absolute alcohol.
Alcohol is alcohol and no one drink is more potent than another, unless they are multiple ounce beverages like Long Island Iced Tea which has between 5 to 7 ounces of alcohol.
How the Body is Affected at Different Levels of BAC
0.02-0.03 BAC: No loss of coordination, slight euphoria and loss of shyness. Depressant effects are not apparent, mildly relaxed and maybe a little lightheaded.
0.04-0.06 BAC: Feeling of well-being, relaxation, lower inhibitions, with a sensation of warmth. There may be euphoria with impairment of reasoning and memory and lowering of caution. A person’s behavior may become exaggerated and emotions intensified with good emotions being better and bad emotions becoming worse.
0.07-0.09 BAC: Impairment of balance, speech, vision, reaction time, and hearing begin. Judgment and self-control are reduced, and caution, reason and memory are impaired, at .08 BAC. In the United States and in the State of Florida, .08 BAC is the presumptive BAC limit at which an individual is presumed to be impaired. You will probably believe that you are functioning better than you really are.
0.10-0.125 BAC: Significant impairment of motor coordination and loss of reasonable judgment. Speech may be slurred; balance, vision, reaction time and hearing will be impaired.
0.13-0.15 BAC: Gross motor impairment and lack of physical control. There will be blurred vision with major loss of balance. Euphoria is reduced and dysphoria (anxiety, restlessness, depression) begin to appear. Judgment and perception are severely impaired and the individual will become disoriented.
0.16-0.19 BAC: Dysphoria predominates, nausea may appear. The impaired individual has the appearance of being impaired. Vision, motor skills, & judgment are further impaired.
0.20 BAC: Feeling dazed, confused or otherwise disoriented a person may need help standing or walking. If they are injured they may not feel the pain. Some people experience nausea and vomiting at this level.
The gag reflex is impaired and the individual can choke on their own vomit. Blackouts are likely at this level so the person may not remember what has happened.
0.25 BAC: All mental, physical and sensory functions are severely impaired. There is an increased risk of asphyxiation from choking on vomit and of serious injury by falls or other mishaps. A person’s comprehension will be greatly reduced.
0.30 BAC: At this level a person will be in a stupor. They have little comprehension of where they are. They may pass out suddenly and be difficult to awaken.
0.35 BAC: This is the level of surgical anesthesia. Coma is possible.
0.40 BAC and up: Onset of coma, and possible death due to respiratory arrest.
