5538895653_5cf1065abd_zDriving while under the influence of drugs and/or alcohol is one of the most dangerous behaviors exhibited by motorists. In all states, those driving with a blood alcohol concentration (BAC) of .08 or higher are considered to be guilty of driving under the influence (DUI), and no additional proof of impairment is necessary.

But for drivers with very low blood alcohol content, there is no safe combination of drinking and driving, according to a 2014 study. Even drivers who are only slightly buzzed are 46 percent more likely to be blamed for a collision than the sober drivers they are involved in an accident with. The study concluded that “there is no threshold — no sudden transition from blameless to blamed drivers at BAC 0.08 percent,” and recommended that U.S. legislators lower the legal limit to 0.05 percent, as in most European countries.

How is Blood Alcohol Content Determined?

A person’s blood-alcohol level is determined according to a variety of factors, including weight, gender, metabolism, body fat percentage, medication, alcohol consumed, and time. While driving with a BAC lower than .08 may not necessarily be illegal, people who drive with lower BAC levels are often still impaired:

  • BAC .01 to .03 — While drivers with low-level BACs may appear normal, tests often show a slight decline in visual and multitasking functions.
  • BAC .03 to .06 — Impairment increases as alertness, judgment, coordination, and concentration abilities begin to be affected.
  • BAC .06 to .10 — Reflexes, reasoning, depth perception, distance viewing, and peripheral vision are seriously impaired. Drivers at this BAC level are 11 times more likely to get into a car accident than a sober person is.
  • BAC .11 to .20 — Slow reaction time, loss of motor control, and slurred speech are usually apparent, and drivers at this high intoxication level would appear very drunk.
  • BAC over .20 — Drivers with this level of impairment lose all judgment and motor function, and may black out and become unconsciousness.
  • BAC over .– Death by alcohol poisoning is a possibility.

Even one drink resulting in a low BAC level has been shown to impair vision and cause a driver to become distracted. There is no reason that anyone should drive a car after drinking – that’s what taxis, shuttle buses, and designated drivers are for.

Zero Tolerance Laws

All states have zero tolerance DUI laws for drivers under the legal drinking age. These laws demand criminal punishments for people under the age of 21 who drive with any trace of alcohol in their bloodstream, or with negligible BAC levels of .01 or .02, as is the law in Colorado, where the charge associated with a DUI for those under age 21 is called an Underage Drinking and Driving Offense (UDD). This charge applies to those who have a BAC at .02 but less than .05, while those with a BAC of .05 and higher will receive the same administrative and criminal penalties as a driver over the age of 21. In many states, these zero tolerance laws also apply to drivers who are operating a vehicle under the influence with children present.

The easiest way to prevent drunk driving is to educate people and encourage them to make better decisions. One drink is one too many if you plan on getting behind the wheel of a motor vehicle, whether you are over the legal limit or not.

Image by Greg Matthews

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