BAC Stands for Blood Alcohol Content (or Concentration). When you drink alcohol, it gets passed directly into your bloodstream. BAC can be measured reliably and accurately. Effects on skills related to driving are very well documented.
Most of the planet is in agreement that driving with a BAC of .08 is too dangerous to allow. This is why laws everywhere are written with 08 being the point of legal intoxication.
At a .08, you experience sedation, slow reaction time, and poor coordination. It's obvious why driving with a .08 is illegal.
At lower levels, sedation and slow reaction time are still factors. It's obvious why driving with lower BAC levels is still dangerous.
If you've been drinking, the only way to get to .00 is to wait at least 45 minutes per drink.
It can take over 2 hours to drop from .05 to .00
That's not just in America. Both North and South American Continents and most of Europe accept .08 as the legal limit for driving.
It can take up to 6 hours for your BAC level to drop from a .08 to a .00
If you are under 21, driving with anything higher than .00 is illegal.
Once alcohol mixes with your blood, there is only one way to get it out of there. You have to wait.
A common guideline is that after each typical drink, you must wait 45 minutes before attempting to drive.
If you have another drink, you must add another 45 minutes.
You've had a drink and must wait 45 minutes before driving. A quarter hour later, you have another drink. Now you must wait 45 minutes PLUS the 30 minutes left over from the first drink. That's one and a quarter hours before you should drive. Got time for another?
Because men and women are built differently, women reach a higher BAC drink after drink than men.
More of the alcohol a woman drinks enters her bloodstream.
The first drink or two are not drastically different and the 45 minute rule should be OK.
If you are having the equivalent of 3 or more drinks, You should add another hour to your wait.
We can't say it enough. After drinking, WAIT before driving. For more details read our Blood Alcohol Content article.