There are two elements that must be proved in every DUI case. One is that you are “operating a vehicle” and the other is that you’re legally impaired, which can be shown in all states with a blood alcohol content (BAC) over .08%.
These two elements are obviously intertwined because if you’re legally impaired, you may not be capable of making an informed decision whether to drive. That is, if you’re asking whether you’re too intoxicated to operate a motor vehicle, the answer is usually “Yes!” After all, any impairment of your senses is hazardous, especially if you’re piloting two tons of steel at 50 miles per hour.
That’s why it’s crucial that you understand how alcohol works and in particular how it affects your BAC.
For information on how much you can “legally” drink, review the article: Blood Alcohol Level Chart: Are You Legally Drunk?
By getting behind the wheel, you’ve already established the first element of a DUI -- you’re operating a motor vehicle.
In other words, the “operation requirement” is satisfied once a police officer or a witness sees you driving, or -- if you’re out of the car when the officer arrives – it is deduced you were driving from the circumstances. In some states, you could be charged with a DUI even you’re found in the car with the engine turned off and the keys in your pocket. In some states it makes no difference where you were operating the vehicle even if it was on your own property. And the vehicle need not be a car. For instance, it is possible to be charged with DUI for operating a golf cart on a private golf course, or while riding a bicycle.
So, if you’re behind the wheel wondering whether you had too much to drink, you’re already asking the wrong question. By the way, the law in every state considers you to be an offender if your BAC is above .08% (and for those under 21 in many states it is .00% or .02%).
But forget about BAC for a moment and consider alcohol’s effects. After only one or two drinks you may suffer from blurred vision, slurred speech, slowed reaction times, and impaired memory. If you have been drinking to excess, you may even suffer from unconsciousness or alcohol poisoning. With every drink, your blood alcohol level (BAC) becomes elevated and each level of BAC has its own effect on the brain as follows:
If you are a minor (or in some states, on probation), you will likely be subject to a zero or low-tolerance statute, which means you can’t drive with more than .02 blood alcohol content, or in about half the states, with any measurable amount of alcohol in your blood. The same is true in some states if you have been previously convicted of a DUI. If your DUI is connected to an injury or death, then you likely will be faced with a felony prosecution, which we also don’t cover here. Many states also make driving with over .15 or .20 BAC a separate and more serious category of DUI. And then there are the second, third, and fourth offense DUIs, which can also result in felony prosecutions. In other words, there are many, many more reasons not to get behind the wheel.