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 Blood Alcohol Concentration Level  

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It is illegal per se (in itself) to drive a motor vehicle with a blood alcohol concentration (BAC) at or above a specified level in all States. The previous level in most states had been .10 BAC for drivers 21 and older, but now 45 States, the District of Columbia, and Puerto Rico have enacted laws that set a lower level of .08 BAC. In a 1992 Report to Congress, NHTSA recommended that all States lower the illegal per se level to .08 for all drivers 21 and older.

In 1998, as part of the Transportation Equity Act for the 21st Century (TEA-21), a new Federal incentive grant was created to encourage States to adopt a .08 BAC illegal per se level.

In 2000, Congress passed the DOT Appropriations Act of FY 2001, adopting .08 BAC as the national illegal limit for impaired driving. The statute provides that States that do not adopt a conforming .08 BAC law by October 1, 2003, will be subject to a withholding 2 percent of certain highway construction funds. Each year, the withholding percentage increases by 2%, up to 8% in FY 2007 and later. Those states that adopt a conforming .08 BAC law within 4 years of any withholding will be re-imbursed for those withheld funds. If a State has not adopted a conform-ing .08 BAC law by October 1, 2007, portions of its withheld funds shall begin to lapse and will no longer be available to the State

Key Facts:

  • In 2002, 41% of the 42,815 motor vehicle deaths were alcohol-related. This translates to 17,419 alcohol-related motor vehicle deaths during that year, accounting for an average of one alcohol-related fatality every 30 minutes.
  • The National Highway Traffic Safety Administration"s (NHTSA) position on the relationship be-tween blood alcohol concentration and driving is that driving performance degrades with every drink.
  • A comprehensive NHTSA study provides what is perhaps clear evidence of the significant impair-ment that occurs in the driving-related skills of all drivers with .08 BAC, regardless of age, gender, or drinking history.
  • .08 BAC laws are effective in re-ducing alcohol-related fatal crashes. At least 10 studies, covering many of the States that have enacted .08 BAC laws, have consis-tently shown that .08 BAC laws are associated with reductions in alcohol-related fatalities, particularly in conjunction with the administrative license revocation (ALR) laws that are present in 41 States.
  • NHTSA has published several comprehensive studies on the effectiveness of .08 BAC laws. These studies found consistent BAC laws are associated with reduced incidence of alcohol-related fatal crashes. A study of the effectiveness of a .08 BAC law implemented in Illinois in 1997, found that the .08 BAC law was associated with a 13.7% decline in the number of drinking drivers involved in fatal crashes. The reduction included drivers at both high and low BAC levels. This is significant because critics of .08 BAC laws have often claimed that these laws do not affect the behavior of high BAC drivers. The study also found that there were no major problems reported by local law enforce-ment or court systems due to the change in the law. An updated analysis of Illinois"s law estimated that 105 lives were saved in the first two calendar years since its implementation.
  • In a comprehensive study of drivers involved in fatal crashes in all 50 states and DC from 1982-1997, it was estimated that .08 BAC laws reduced driver alcohol-related fatal crashes by 8%.
  • A 1999 report by the U.S. General Accounting Office (GAO) reviewed the studies available at that time and found strong indications that .08 BAC laws, in combination with other drunk driving laws (particularly license revocation laws), sustained public education and information efforts, and vigorous and consistent enforcement, can save lives. The GAO report also concluded that a .08 (BAC) law can be an important component of a State"s over-all highway safety program.

Why .08?:

The research is clear. Virtually all drivers, even those who are experienced drinkers, are significantly impaired at a .08 BAC. As early as 1988, a NHTSA review of 177 studies clearly documented this impairment. NHTSA released a later review of 112 more recent studies, providing additional evidence of impairment at .08 BAC and below. The results of the nearly 300 studies reviewed have shown that, at a .08 BAC level, virtually all drivers are impaired in the performance of critical driving tasks such as divided attention, complex reaction time, steering, lane changing, and judgment.

The risk of being in a crash gradually increases as a driver"s BAC increases, but rises more rapidly once a driver reaches or exceeds .08 BAC compared to drivers with no alcohol in their blood stream. A recent study estimated that drivers at .08 to .09 BACs are anywhere from 11 to 52 times more likely to be involved in a fatal crash than drivers at .00 BAC, depending upon their age and gender.

Lowering the per se limit is an effective countermeasure that will reduce alcohol-related traffic fatalities, especially when combined with an ALR law. There was a 12 percent reduction in alcohol-related fatalities in California in 1990 after a .08 and an ALR law went into effect. The decrease in alcohol-related fatali-ties occurred at both high and low BAC levels, including drivers with BAC levels of .20 or greater. A 1996 study at Boston University showed that States adopting .08 laws experienced 16% and 18% post-law declines in the proportions of fatal crashes involving fatally-injured drivers whose BAC levels were .08 or higher and .15 or higher, respectively. The Centers for Disease Control (CDC) and Prevention concluded that .08 BAC laws are associated with a median 7% reduction in alcohol-related traffic fatalities in States that adopt them.

The .08 BAC limit is reasonable and has the potential for saving hundreds of lives and reducing thousands of serious injuries each year, if implemented by all States.

The public supports a .08 BAC level. A survey conducted in 2001 indicated that 88% of the people in States with .08 laws support the law.

Point-Counterpoint:

States considering .08 BAC laws should review all the facts, including the rationale behind the .08 goal and the potential impact on alcohol-related deaths. Opposition to .08 laws generally includes the following arguments:

Point: In 1999, the U.S. General Accounting Office (GAO) conducted a critical review of the .08 studies and concluded that these laws are not effective in reducing alcohol-related fatalities.

Counterpoint: This statement is not correct! The GAO report stated that there are "strong in-dications that .08 BAC laws, in combination with other drunk driving laws (particularly license revocation laws), sustained public education and information efforts, and vigorous and consistent enforcement, can save lives"

Point: ".08 BAC legislation will not affect problem drinker drivers who have high BAC levels."

Counterpoint: The latest research shows that .08 BAC laws not only reduce the incidence of impaired driving at lower BAC levels, they also reduce the incidence of impaired driving at higher BAC levels (i.e., over .10). A .08 BAC law serves as a general deterrent to all those who drink and drive because it sends a message that the State is getting tougher on impaired driving, and it makes many people think twice about getting behind the wheel after they have had too much to drink. A .08 BAC law should be a key component of any State"s overall program to reduce impaired driving. While repeat offenders do ac-count for a significant part of the problem, most fatally-injured drinking drivers have no prior alcohol-related offenses.

Point: .08 BAC laws make criminals out of normal social drinkers.

Counterpoint: Impairment and crash risk are the issues, not how many drinks it may take to get to a .08 BAC level. Numerous studies have indicated that at a .08 BAC level, virtually all drivers are impaired on critical driving tasks such as divided attention, complex reaction time, steering, lane changing, and judgment.

In addition, studies have shown that the risk of being involved in a fatal crash is much greater than at a .08 BAC level.

Point: ".08 is just the first step in a movement toward zero tolerance."

Counterpoint: A .08 BAC limit is not meant to restrict individuals from drinking alcohol. Rather, the limit exists to prevent individuals from operating a motor vehicle while impaired by alcohol, putting their own lives, and the lives of others at risk.

Point: .08 BAC laws will overwhelm police and clog the criminal justice system.

Counterpoint: Two studies, one in California and another in Illinois, looked at the impact of .08 BAC laws on enforcement efforts and the criminal justice system. These studies have not found any significant problems with the enforcement of lower BAC limits for police or the State courts.

.05 BAC Limit in Other Countries:

The international trend continues to be to reduce illegal per se limits to .05 BAC or lower. The illegal limit is .05 BAC in numerous coun-tries, including Australia, Belgium, Bulgaria, Denmark, Finland, France, Germany, Greece, Ireland, Israel, The Netherlands, Portugal, Russia, South Africa, Spain, and Turkey. Russia, Sweden and Norway have a limit of .02 BAC and Poland recently went to .03 BAC. Several countries have reported studies indicating that lowering the illegal per se limit from .08 BAC to .05 BAC reduces alcohol-related fatalities (e.g., Australia, Austria, Belgium, The Netherlands and France).

Laboratory studies from these countries indicate that impairment in critical driving functions begins at low BACs. Most subjects in these studies were significantly impaired at .05 BAC with regard to visual acuity, vigilance, drowsiness, psychomotor skills, and information processing, compared to their per-formance at .00 BAC.

Leading medical, crash prevention, public health and traffic safety organizations in the world support BAC limits at .05 or lower, including: the World Medical Association, the American and British Medical Associations, the European Commission, the European Transport Safety Council, the World Health Organization and the American College of Emergency Physicians.

Author - National Highway Traffic Safety Administration
Published - 3/1/2004
Publisher - NHTSA website
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