.08: Why is this the “Magic” Number?

What makes someone unfit to drive after their BAC exceeds .08?

Bill weighs 170 pounds. After drinking five beers in two hours, his blood alcohol content (BAC) will be over .08 percent. His wife, Tammy, weighs 120. Her BAC will reach .08 during that same time period after just three beers.

According to laws across all 50 states, Bill and Tammy will have both surpassed the legal limit for driving. Why? What’s so special about .08?

Based on research, scientists determined that our coordination is noticeably impaired at this level. Having a BAC over .08 impairs our ability to correctly get signals from our brains – to either our hands on the steering wheel or our feet on the brake pedal. The alcohol delays our reaction time too much and prevents us from driving safely.

A Bit of BAC History…

Back in the late 1990s, this BAC law was not uniform. Laws in some states stipulated a legal driving limit of .10. Others had the currently established .08 limit. Believe it or not, two states had no BAC limit law at all.

When the push came to standardize safe blood alcohol levels across the nation, the federal government offered states with higher limits a financial incentive to lower it to .08 percent. The result is the standard we have today.

Is Our Standard World-Wide?

No…not even close. In fact, the U.S. has one of the highest legal drinking limits in the world.

  • Sweden, Norway and China are among the many countries that have legal limits of .02.
  • Afghanistan and Brazil both have zero tolerance.
  • Many nations have chosen .05 as the legal limit. Based on results from other countries, lowering our limit to .05 would save hundreds of lives each year.

Will the U.S. Lower its BAC Limit?

The National Transportation Safety Board has recommended in the past that the limit be reduced to .05 percent. Apparently, other countries agree. However, arguments on the other side point out that this limit can be reached by some adults with just one drink. The change, it is argued, would only inhibit safe drivers and not stop those who would drive whether their limit is over .05 or .08.

Other campaigns call for different solutions to drunk driving. These ask for strict laws revoking a person’s license at their first DUI offense, or mandatory installation of ignition locks, which require the driver to pass a breathalyzer before the car is operable.

Since it’s possible lowering the legal limit would save lives, why don’t we do it? Two main reasons keep popping up:

  • Powerful Industries

    The alcohol lobby and restaurant industry are huge. If the limit were reduced, many who rely on alcohol sales would fear closing up shop. While these groups make efforts to encourage safe driving and oppose drunk driving, they will not go as far as supporting efforts that will put them out of business.
  • Lenient Laws for Liberty

    Our nation’s backbone is a spirit of individualism and liberty. When we try to put laws into place that limit our freedoms, many people don’t like it – even when the laws are for our own protection and the safety of others we may endanger, it is common for the proposed changes to receive strong opposition. We tend to lean toward lenience to avoid trampling rights. The result is a higher legal diving limit than is acceptable in many other parts of the world.


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