Alcohol and driving: How much is too much?

In the United States, a 0.08 blood alcohol level is the legal limit for driving while intoxicated. However, legal limits do not define a level below which it is safe to operate a vehicle. Studies have concluded that the risk for crashes, including fatal crashes, goes up as BAL levels increase even if it is well below the legal limit of 0.08. Because alcohol is a depressant, it:

-Slows reaction time when driving

-Upsets our coordination and balance

-Impairs hearing and vision.

-Makes us drowsy and sleepy and lose concentration

-Affects our judgment and reasoning

-Makes us take excessive risks

Because of this, blood alcohol levels well below the legal limit are associated with car crashes that cause incapacitating injury and death, according to the Center for Disease Control.

David Philips, Ph.D. and a sociologist at University of California, San Diego, says; “No amount of alcohol seems to be safe for driving.” Because alcohol slows reaction time and impairs judgment and coordination, important skills necessary to safe driving, even a small amount of alcohol will diminish anyone’s driving ability. Furthermore, in the study, drivers who tested positive for blood alcohol levels well below the legal blood alcohol content limit were more likely to be in severe car crashes than sober drivers largely because they drove significantly faster, were less likely to be appropriately using a seat belt, and were usually driving the striking vehicle.

When I speak to groups about this, I often use the following example. Driver A stops at a stop sign at an intersecting road but fails to see an oncoming vehicle driven by driver B, resulting in a collision. The obvious cause of this crash is the failure of driver A to yield to oncoming traffic. However, driver B had consumed one beer within the past hour and would perhaps test at a BAC level of perhaps 0.02 or 0.03, not even at the limit for driving while ability impaired. However, the effect of the one beer slightly diminished driver B’s reaction time and coordination. If driver B had not had any alcohol, he/she might have been able to avoid the collision entirely.

I mentioned at the beginning of this article that the legal BAC level for DWI in the U.S. is 0.08. What you may not be aware of is that this level is among the highest in the world, and those countries that have a 0.08 BAC limit are in the minority. Most countries in the world consider drunk driving at a BAC level of 0.05 or below. Most European countries have a limit of 0.05. Norway and Sweden are 0.02. A few countries, including Russia, have zero tolerance for drinking and driving.

So, the next time you drive after consuming a few beers, be aware that even if you are not legally drunk, your ability to drive safely is compromised.

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