Alcohol: whether you consider it a blessing or a vice, it is a fact of life that has been part of the human experience for as long as recorded history. It encouraged the development of irrigation in ancient Mesopotamia, provided the wages (and many of the calories) for the builders of the Great Pyramids of Giza, and was instrumental in the spread of classical culture throughout Europe. Notwithstanding this long history, the availability of significantly stronger alcoholic beverages today has made it a highly-regulated substance – particularly in Utah – and with good reason, as any victim of a DUI-related accident can attest. But despite the widespread awareness of the danger posed by impaired drivers, for those who consume alcohol the question remains: how much alcohol can a person drink before they are no longer safe to drive?
STATE REGULATIONS
The most obvious place to begin is the legal limit as defined by the state. The Utah Legislature has passed very specific laws pertaining to the consumption of alcohol and the operation of motor vehicles, declaring that “a person may not operate or be in actual physical control of a vehicle within this state [Utah] if the person: (a) has sufficient alcohol in the person’s body that a subsequent chemical test shows that the person has a blood or breath alcohol content of .08 grams or greater at the time of the test.”[1]
While most people are probably familiar with this .08 limit, the legislature added a significant caveat to that law when they determined that an individual “under the influence of alcohol, any drug, or the combined influence of alcohol and any drug to a degree that renders the person incapable of safely operating a vehicle,” is in violation of the law.[2] In short, if an officer is able to procure evidence that a driver was impaired while operating a vehicle – regardless of the actual amount of alcohol (or other drugs) the driver might have in their system – the driver can be charged with a DUI. In fact, according to the Twelfth Annual DUI Report to the Utah Legislature, some 544 individuals with a BAC (blood/breath alcohol concentration) at or below .07 were arrested for DUI in 2014 alone.
Although anyone consuming any quantity of alcohol (or other drug) is at risk of being charged with a DUI regardless of the amounts in their systems at the time of a test, the vast majority of DUI charges are nevertheless incurred by individuals who test at or above the .08 BAC limit. Given that, it is important to be aware of the signs that suggest you may have reached or exceeded the legal limit.
INDICATORS OF THE .08 LIMIT
The fact is that every individual metabolizes and processes alcohol at different rates: according to NHTSA (the National Highway Traffic Safety Administration), everything from a person’s weight to the amount of food they’ve consumed can affect how quickly their BAC level reaches .08. That said, the approximations provided to the Utah Legislature in the 2014 DUI report reveal just how quickly an individual might reach .08; according to that report, it takes around 4 beers for an average 160 pound male to reach a BAC level of .08. Given how particular this estimation is, it is perhaps more useful to examine the symptoms of the .08 BAC condition.
Among the most specific indicators of a typical BAC level of .08 is a decrease in the ability to coordinate muscular activities. According to NHTSA, difficulty in keeping balance, blurred vision, slurred speech, slow reaction time and reduced hearing are all typical indicators of decreased muscle coordination. This reduced coordination leads to a decline in one’s ability to detect danger (given the difficulties in seeing and/or hearing), and consequently an inability to reason or exercise judgement as effectively as a sober driver might. Given the implications such impairment might have when operating a vehicle, it seems obvious why the current legal limit has been set at .08. Yet NHTSA goes on to report that such impairment typically has only a minor impact on driving; an inability to maintain constant speed and difficulty in detecting signals are among the only indications that a person is operating a vehicle at a BAC level of around .08.
With such subtle indicators, it probably comes as no surprise that police officers are willing to detain a driver for a DUI investigation when only minor traffic violations are observed: simply forgetting to signal or driving at a few miles over the speed limit might be construed as indications of impaired driving. But supposing that an individual recognizes they have reached the .08 limit, how much time must they wait before they are able to drive legally?
METABOLIZING RATE
As with the amount of time it takes to reach the .08 limit, the amount of time each individual might require to return their BAC level back within the legal limit is similarly difficult to estimate. Ideally a simple absence of the symptoms of a .08 BAC level as described above would be indication enough, but the fact is that a tolerance to alcohol might negate the symptoms (but not the BAC level), and heavy drinkers might not even be capable of distinguishing the symptoms from their normal state of mind. An individual might even believe they are safe to drive simply because they have eaten prior to or while drinking, which can delay the onset of the effects of alcohol: a person might go from driving below the legal limit to driving above the legal limit right in the middle of their commute.
In short, and as NHTSA recommends, driving after consuming any amount of alcohol should be avoided. Arranging for a designated driver, taking a taxi, using public transportation or simply spending the night before driving have all been suggested as precautionary measures meant to reduce the chance that you might drive in violation of the law. Given the consequences a DUI can have on everything from your license to your job – to say nothing of the danger posed to others while operating a vehicle in such a condition – it is probably best to err on the side of caution. If you plan to drink, don’t plan on driving.
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