How Do You Know That You Are Legally Drunk?

It's really not a question of whether or not you’re legally drunk. It's a question of whether or not it is safe for you to get behind the wheel of a motor vehicle when you have consumed any amount of alcohol. Recent research shows that driving impairment starts long before a person reaches the blood alcohol concentration level necessary to be guilty of drunken driving. After reading this article, you can decide whether you’ll need a designated driver, cab or luxury sedan next time you go out to party.

In all 50 states, the legal limit for drunk driving is a blood alcohol concentration (BAC) level of .08. That means a 120-pound woman can reach a .08 BAC level after only two drinks and a 180-pound man can be at .08 after only four drinks. A "drink" in this case is either one shot of liquor, a five-ounce glass of wine or one beer, all of which contain the same amount of alcohol.

At a .08 BAC level, drivers are so impaired that they are 11 times more likely to have a single-vehicle crash when compared drivers who have had no alcohol at all. But 25 years of research has shown that some impairment begins for both sexes even after one drink.
At the .02 blood alcohol level, experiments have shown that people have some loss of judgment, begin to relax and feel good. But tests have also shown that drivers at the .02 level experience a decline in visual functions, affecting their ability to track a moving object, as well as experience a decline in the ability to perform two tasks at the same time.

These changes are barely noticeable to the person who has had only one drink. But in an emergency situation, while behind the wheel of a vehicle, this drink could impair the driver’s reactions as they would without having had a drink.

At the .05 BAC level, people begin to show exaggerated behavior, experience loss of small-muscle control -- such as being able to focus their eyes quickly -- while having impaired judgment, lowered alertness and a release of inhibition.

If someone with a BAC level of .05 gets behind the wheel, they would be operating the vehicle with diminished coordination, a further reduced ability to track moving objects, more difficulty in steering and a very reduced response in emergency situations.
When someone drinking is approaching the edge of legal intoxication, studies show that he or she has poor muscle coordination -- affecting their balance, speech, vision, reaction time and hearing. This individual finds it more difficult to detect danger, and exhibit impaired judgment, self-control, reasoning ability and memory.

A driver with a BAC of .08 will find it more difficult to concentrate, judge the speed of the vehicle, experience reduced information processing capability and exhibit impaired perception.

When you drink alcohol, your impairments may be hardly noticeable at the time, but the slow reaction times that they can produce could prove fatal in an emergency-driving situation. So it’s truly not a good idea to drive no matter how much or how little that you have had to drink.

Here’s something else to consider -- alcohol affects people differently. Some people have a higher response to drinking alcohol than others. This means that people with a high response to alcohol can experience signs of impairment at the .02 BAC level that others do not experience until the .05 level.

For this reason, in some states, drivers can be arrested for driving while impaired, even if their blood alcohol concentration is lower than the legal limit. Especially if the law enforcement officer believes he or she has probable cause based on the behavior and reactions of the driver.