oversight

Highway Safety: Effectiveness of State .08 Blood Alcohol Laws

Published by the Government Accountability Office on 1999-06-23.

Below is a raw (and likely hideous) rendition of the original report. (PDF)

                  United States General Accounting Office

GAO               Report to Congressional Committees




June 1999
                  HIGHWAY SAFETY
                  Effectiveness of State
                  .08 Blood Alcohol Laws




GAO/RCED-99-179
      United States
GAO   General Accounting Office
      Washington, D.C. 20548

      Resources, Community, and
      Economic Development Division

      B-280883

      June 23, 1999

      The Honorable John McCain
      Chairman
      The Honorable Ernest F. Hollings
      Ranking Minority Member
      Committee on Commerce, Science,
        and Transportation
      United States Senate

      The Honorable Bud Shuster
      Chairman
      The Honorable James L. Oberstar
      Ranking Democratic Member
      Committee on Transportation and Infrastructure
      House of Representatives

      In 1997, someone in the United States died in an alcohol-related motor
      vehicle crash every 32 minutes. For years, the Congress and the states
      have grappled with and sought solutions to the problem of drunk driving.
      Most states have laws making it illegal for people to drive with a specified
      level of alcohol in their blood, usually set at .10 blood alcohol
      concentration (BAC)—the level at which a person’s blood contains 1/10th
      of 1 percent alcohol. However, 16 states have more stringent laws setting
      the limit at .08 BAC. In 1998, the Clinton administration endorsed a bill that
      would have required all states to enact and enforce .08 BAC laws or face
      reductions in federal highway funds. The Senate approved this bill; the
      House took no action.

      The Transportation Equity Act for the 21st Century directed GAO to
      evaluate the effectiveness of state .08 BAC laws in reducing the number and
      severity of crashes involving alcohol.1 To accomplish this objective, we
      reviewed (1) the policies and positions of the Department of
      Transportation’s (DOT) National Highway Traffic Safety Administration
      (NHTSA) on .08 BAC laws and other drunk driving countermeasures and
      (2) seven published studies on the effect of .08 BAC laws on the number
      and severity of crashes involving alcohol, including three studies released
      on April 28, 1999.

      1
       The Transportation Equity Act for the 21st Century also directed us to study the effectiveness of .02
      BAC laws for drivers under 21 in reducing the number and severity of crashes involving alcohol. The
      National Highway System Designation Act of 1995 required all states to enact and enforce such laws or
      face reductions in federal highway funds. However, as agreed to by your staff, we will not address the
      impact of .02 BAC laws, since all 50 states and the District of Columbia now have laws establishing
      BAC levels of .02 or less for drivers under 21.



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                   Overall, the evidence does not conclusively establish that .08 BAC laws, by
Results in Brief   themselves, result in reductions in the number and severity of
                   alcohol-related crashes. There are, however, 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. For example, while
                   two studies have concluded that California’s .08 BAC law was not directly
                   associated with the decline in drunk driving deaths the state experienced
                   in the early 1990s, these studies found that the .08 BAC law was effective
                   when paired with the state’s license revocation law, which took effect 6
                   months later.

                   Until recently, only four published studies examined the effectiveness of
                   .08 BAC laws in five states and, while NHTSA characterized the studies as
                   conclusively establishing that .08 BAC laws by themselves were effective,
                   the studies had limitations and raised methodological concerns calling
                   their conclusions into question or reported mixed results. In April 1999,
                   three additional studies were released that were more comprehensive and
                   showed many positive results but nevertheless fell short of providing
                   conclusive evidence that .08 BAC laws were, by themselves, responsible for
                   reductions in alcohol-related crashes and fatalities. It is difficult to
                   accurately predict how many lives would be saved if all states enacted .08
                   BAC laws because whether a state sees reductions after enacting a .08 BAC
                   law depends on a number of factors, including the degree to which the law
                   is publicized, how well it is enforced, other drunk driving laws in effect,
                   and public attitudes concerning alcohol. Despite the absence of a strong
                   causal link between .08 BAC laws by themselves and reductions in traffic
                   fatalities, other evidence, including medical evidence on drivers’
                   impairment, should be considered when evaluating the effectiveness of .08
                   BAC laws.2



                   It is illegal in every state and the District of Columbia to drive a motor
Background         vehicle while under the influence of alcohol. In addition, all states but two
                   have blood alcohol “per se” laws—laws that make it unlawful for a person
                   to drive a motor vehicle with a specific amount of alcohol in his or her
                   blood. As figure 1 shows, 32 states and the District of Columbia have set
                   that amount at .10 BAC. In 16 states, the per se limit is 20 percent lower, or
                   .08 BAC.


                   2
                    Because the Transportation Equity Act for the 21st Century directed us to review the effectiveness of
                   .08 BAC laws in reducing the number and severity of crashes involving alcohol, we did not evaluate the
                   medical impairment evidence.



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Figure 1: State Blood Alcohol “per Se” Laws




                        1999

                                                                                                                                        1988

                                                                                                                                 1991
                    1983
                                                                                                                                    1994
                                    1997




                                       1983                                              1997

               1990
                                                                  1993                                                1994


                                                                                                                      1993

                                              1994


                                                                                                  1995




                                                                                                                   1994




                                                          1995




         State with .08 BAC law

         State with .10 BAC law

         State with no per se law




                                              Note: States with .08 BAC laws are shown with the year the law became effective.

                                              Source: GAO’s illustration based on information from NHTSA.




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On average, according to NHTSA, a 170-pound man reaches .08 BAC after
consuming five 12-ounce beers (4.5-percent alcohol by volume) over a
2-hour period. A 120-pound woman reaches the same level after
consuming three beers over the same period. NHTSA publishes a BAC
estimator that computes the level of alcohol in a person’s blood on the
basis of the person’s weight and gender and the amount of alcohol
consumed over a specified period of time. This estimator assumes average
physical attributes in the population—in reality, alcohol affects individuals
differently, and this guide cannot precisely predict its effect on everyone.
For example, younger people have higher concentrations of body water
than older people; therefore, after consuming the same amount of alcohol,
a 170-pound 20-year-old man attains a lower BAC level on average than a
170-pound 50-year-old man.

As figure 2 illustrates, NHTSA’s estimator shows that the difference between
the .08 BAC and .10 BAC levels for a 170-pound man is one beer over 2 hours.
The difference between the .08 BAC and .10 BAC levels for a 120-pound
woman is one-half a beer over the same time period.




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Figure 2: Alcohol Consumption and Blood Alcohol Levels




    170 lb.
     Man


                              .02            .04                .06                 .08              .10




   120 lb.
   Woman

                             .02             .04                 .06                .08              .10

Drinks consumed in a 2-hour period


   12-ounce beer (4.5% alcohol by volume)

   1/2 beer
   1/4 beer

                                        Source: GAO’s illustration based on NHTSA’s BAC estimator.




                                        Alcohol use is a significant factor in fatal motor vehicle crashes. In 1997,
                                        the most recent year for which data are available, there were 16,189
                                        alcohol-related fatalities, representing 38.6 percent of the nearly 42,000
                                        people killed in fatal crashes that year. In the states with .08 BAC laws,
                                        alcohol was involved in 36 percent of all traffic fatalities, lower than the
                                        national average and the 39.5-percent rate of alcohol involvement in the




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rest of the states.3 Utah had the lowest level at 20.6 percent; the District of
Columbia had the highest at 58.5 percent. Among the 10 states with the
lowest levels of alcohol-related fatalities, 3 were states with .08 BAC laws
and 7 were states with .10 BAC laws. Among the 10 states with the highest
levels of alcohol-related fatalities, 2 were states with .08 BAC laws, 7 were
states with .10 BAC laws, and 1 had no BAC per se law.

Although alcohol use remains a significant factor in fatal crashes, fatalities
involving alcohol have declined sharply over the last 15 years. In 1982,
25,165 people died in crashes involving alcohol, 57.3 percent of the nearly
44,000 traffic fatalities that year. The proportion of fatal crashes that
involved alcohol declined during the 1980s, falling below 50 percent for
the first time in 1989. The involvement of alcohol in fatal crashes declined
markedly in the early 1990s, from about 50 percent of the fatal crashes in
1990 to nearly 40 percent in 1994. During this time, the number of people
killed in crashes involving alcohol declined by around 25 percent. The
proportion of fatalities involving alcohol rose slightly in the next 2 years
before falling, in 1997, to its lowest level since 1982, as figure 3 shows.




3
 This analysis excludes Idaho and Illinois, states that had .08 BAC laws take effect during 1997.



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Figure 3: Alcohol-Related Fatalities,
1982-97
                                        80       Percentage of all fatalities that are alcohol-related




                                        60




                                        40




                                        20
                                            82


                                                   83


                                                          84


                                                                 85


                                                                         86


                                                                                87


                                                                                        88


                                                                                               89


                                                                                                         90


                                                                                                              91


                                                                                                                   92


                                                                                                                        93


                                                                                                                             94


                                                                                                                                  95


                                                                                                                                       96


                                                                                                                                             97
                                        19


                                                   19


                                                         19


                                                                19


                                                                        19


                                                                               19


                                                                                      19


                                                                                              19


                                                                                                     19


                                                                                                              19


                                                                                                                   19


                                                                                                                        19


                                                                                                                             19


                                                                                                                                  19


                                                                                                                                       19


                                                                                                                                            19
                                            Year



                                        Source: GAO’s illustration based on NHTSA’s Traffic Safety Facts, 1997.




                                        Each state reports, and NHTSA collects and publishes, data on fatal crashes
                                        through the Fatal Accident Reporting System (FARS), a comprehensive
                                        national database of all crashes in which a person dies within 30 days of
                                        the crash. These data include (1) the number of fatalities that occur in all
                                        crashes and (2) the number of drivers involved in fatal crashes. FARS also
                                        includes whether crashes involved drivers who had been drinking.
                                        However, FARS has limitations regarding alcohol involvement in
                                        crashes—for example, fewer than half of the drivers at the scene of fatal
                                        accidents are tested for alcohol. To address the missing data, NHTSA
                                        developed a statistical model, first used in 1982, to estimate alcohol
                                        involvement in cases in which data are not available. The model provides
                                        estimates in three broad categories—sober (.00 BAC), “low BAC” (.01- .09
                                        BAC), and “high BAC” (.10 BAC and above).4 Therefore, certain
                                        questions—such as how many fatal crashes involve drivers with .08 BAC

                                        4
                                         When cataloguing fatalities in crashes in which more than one driver had been drinking, FARS uses
                                        the driver with the higher BAC.



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                      levels versus other levels or what the average BAC of drunk drivers
                      involved in fatal crashes is—cannot be reliably answered by this model.
                      NHTSA plans to release a new model in 1999 that will estimate specific BAC
                      levels.


                      NHTSA  believes that the best countermeasure against drunk driving is a
NHTSA Believes All    combination of laws, public education, and enforcement. Since 1970, NHTSA
States Should Have    has espoused a “systems approach” to reducing drunk driving including
Alcohol Deterrence    enforcement, judicial, legislative, licensing, and public information
                      components. In 1997, NHTSA published an action plan developed with other
Measures, Including   participants to reduce alcohol-related driving fatalities to 11,000 by the
.08 BAC Laws          year 2005. This plan recommended that all states pass a wide range of
                      laws, including ones establishing .08 BAC limits, license revocation
                      laws—under which a person deemed to be driving under the influence has
                      his or her driving privileges suspended or revoked, comprehensive
                      screening and treatment programs for alcohol offenders, vehicle
                      impoundment, “zero tolerance” BAC and other laws for youth, and
                      primary enforcement laws for safety belts.5 The plan also called for
                      increased public awareness campaigns, with an emphasis on target
                      populations such as young people and repeat offenders. Similarly, “The
                      Presidential Initiative for Making .08 BAC the National Legal Limit,”
                      published by NHTSA in August 1998, contained a four-point plan that
                      recommended the expansion of public education campaigns; the building
                      of public-private partnerships; and active, high-visibility enforcement of
                      several alcohol laws.

                      The value of public education and enforcement has been demonstrated in
                      a number of studies. A recent NHTSA evaluation of a sobriety checkpoint
                      program in Tennessee, a state with a .10 BAC limit, concluded that the
                      program and its attendant publicity reduced alcohol-related fatal accidents
                      in that state by 20.4 percent. A systems approach to traffic safety is not
                      limited to preventing drunk driving. Our January 1996 report concluded
                      that the states that have been most successful at increasing safety belt use
                      among all drivers are the ones with primary enforcement laws, visible and
                      aggressive enforcement, and active public information and education
                      programs.6


                      5
                       Primary enforcement laws permit officials to enforce safety belt requirements independently of other
                      traffic safety laws, in contrast to secondary enforcement laws, which allow officials to enforce safety
                      belt requirements only when other traffic safety laws are being enforced.
                      6
                       Motor Vehicle Safety: Comprehensive State Programs Offer Best Opportunity for Increasing Use of
                      Safety Belts (GAO/RCED 96-24, Jan. 3, 1996).



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                                    Since 1992, when it first recommended in a report to the Congress that all
                                    states have .08 BAC laws, NHTSA’s position has changed from urging the
                                    states to pass .08 BAC laws to favoring that states be required to do so. The
                                    latter position was embodied in the President’s endorsement of a Senate
                                    bill entitled the Safe and Sober Streets Act. This bill would have required
                                    all states to enact and enforce .08 BAC laws by October 1, 2001, or lose
                                    5 percent of certain federal highway funds the first year and 10 percent
                                    each succeeding year. The Senate approved this bill on March 4, 1998, but
                                    the House took no action before the 105th Congress adjourned.7

                                    As figure 4 shows, NHTSA has a number of reasons why it believes all states
                                    should adopt .08 BAC laws.

Figure 4: NHTSA’s Reasons Why All
States Should Adopt .08 BAC Laws
                                    • Virtually all drivers are substantially impaired at .08 BAC with regard to critical driving
                                    tasks.

                                    • The risk of being in a crash increases substantially when a driver reaches .08 BAC.

                                    •.08 is a reasonable level to set the limit.

                                    • The public supports lower BAC limits.

                                    • Other industrialized nations have .08 or lower BAC laws.

                                    • Lowering the limit to .08 is a proven effective countermeasure that will reduce crashes
                                    and save lives.

                                    One of NHTSA’s principal arguments for nationwide adoption of .08 BAC
                                    laws is that the medical evidence of drivers’ impairment at that level is
                                    substantial and conclusive. According to NHTSA, and as shown in figure 5,
                                    reaction time, tracking and steering, and emergency responses are
                                    impaired at even low levels, and substantially impaired at .08 BAC. As a
                                    result, the risk of being in a motor vehicle crash increases when alcohol is
                                    involved, and increases dramatically at .08 BAC and higher levels. In
                                    contrast to NHTSA’s position, industry associations critical of .08 BAC laws
                                    contend that .08 BAC is an acceptable level of impairment for driving a
                                    motor vehicle and that these laws penalize “responsible social drinking.”
                                    These associations also believe that .08 BAC laws do not address the
                                    problem of drunk driving because many more drivers using alcohol are
                                    reported at the “high” BAC levels (above .10 BAC) than the lower BAC levels.


                                    7
                                     The Senate approved this bill as an amendment to its surface transportation reauthorization bill.
                                    However, these provisions were not included in the House bill and were not included in the final
                                    version of the Transportation Equity Act for the 21st Century.



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                                                          Because we were directed to review the impact of .08 BAC laws on the
                                                          number and severity of crashes involving alcohol, we did not review the
                                                          medical evidence on impairment or other arguments in favor of or in
                                                          opposition to .08 BAC laws.



Figure 5: NHTSA’s Position on Medical Evidence of Drivers’ Impairment

Task Affected

Attention,
reaction time,
visual function

Tracking and steering


Eye movement control,
standing steadiness,
emergency responses


Coordination


Information processing,
judgment


Concentrated attention,
speed control


                           .02                      .04                   .06                   .08                .10          .12
                           .BAC level

                   Indicates the effect from alcohol begins


                                                          Source: GAO’s illustration based on information from NHTSA.




                                                          NHTSA also believes that lowering the BAC limit to .08 is a proven effective
                                                          measure that will reduce the number of crashes and save lives. For
                                                          example, in a December 1997 publication, NHTSA stated that “recent
                                                          research . . . has been quite conclusive in showing the impaired driving
                                                          reductions already attributable to .08, as well as the potential for saving
                                                          additional lives if all states adopted .08 BAC laws” (emphasis added). In




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                       May 1998, the NHTSA Administrator stated, “The traffic safety
                       administration is aware of four published studies, . . . [and] each study has
                       shown that lowering the illegal blood alcohol limit to .08 is associated with
                       significant reductions in alcohol-related fatal crashes.” In a fact sheet
                       distributed to state legislatures considering these laws, NHTSA stated that
                       the agency’s “analysis of five states that lowered the BAC limit to .08
                       showed that significant decreases in alcohol-related fatal crashes occurred
                       in four out of the five states as a result of the legislation” (emphasis
                       added). NHTSA used these study results to encourage states to enact .08 BAC
                       laws, testifying in one instance before a state legislature, “We
                       conservatively project a 10-percent reduction in alcohol-related crashes,
                       deaths, and injuries” in the state.


                       Seven studies have been published assessing the effect of .08 BAC laws on
Seven Studies Have     motor vehicle crashes and fatalities in the United States. Four studies
Examined the           published between 1991 and 1996 assessed the effectiveness of .08 BAC
Effectiveness of .08   laws in the five states that enacted them between 1983 and 1991. On
                       April 28, 1999, NHTSA released three additional studies. Table 1 summarizes
BAC Laws               the seven studies that examine .08 BAC laws.




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Table 1: Studies on the Effectiveness of .08 BAC Laws
Title of study              Released            Conducted by             Funded by                      Scope
The Effects Following the      1991           Research and Evaluation NHTSA                             California
Implementation of an .08                      Associates
BAC Limit and an
Administrative Per Se Law
in California
A Preliminary Assessment       1994           NHTSA staff                NHTSA                          California, Utah, Oregon,
of the Impact of Lowering                                                                               Maine, and Vermont
the Illegal BAC Per Se Limit
to .08 in Five States
The General Deterrent          1995           Department of Motor        California Office of Traffic   California
Impact of California’s .08%                   Vehicles, State of         Safety
Blood Alcohol                                 California
Concentration Limit and
Administrative Per Se
License Suspension Laws
Lowering State Legal Blood 1996               Researchers from           Grants, including ones from California, Utah, Oregon,
Alcohol Concentration                         Boston University’s        the National Institute on   Maine, and Vermont
Limits to .08%: The Effect                    School of Public Health    Alcohol Abuse and
on Fatal Motor Vehicle                                                   Alcoholism and the U.S.
Crashes                                                                  Centers for Disease Control
                                                                         and Prevention
The Effects of 0.08 Laws       1999           Rainbow Technology         NHTSA                          California, Utah, Oregon,
                                              Inc., and NHTSA’s                                         Maine, Vermont, New
                                              National Center for                                       Hampshire, North Carolina,
                                              Statistics and Analysis                                   Kansas, New Mexico,
                                                                                                        Florida, and Virginia.
Evaluation of the Effects of 1999             University of North        NHTSA                          North Carolina
North Carolina’s 0.08% BAC                    Carolina
Law

The Relationship of Alcohol    1999           Pacific Institute for   NHTSA                             50 states and the District of
Safety Laws to Drinking                       Research and Evaluation                                   Columbia
Drivers in Fatal Crashes



The First Four Published                  Although NHTSA characterized the first four studies on the effectiveness of
Studies Had Limitations                   .08 BAC laws as conclusively establishing that .08 BAC laws resulted in
and Raised Methodological                 substantial reductions in fatalities involving alcohol, we found that three
                                          of the four studies had limitations and raised methodological concerns
Concerns                                  that called their conclusions into question. For example, while a
                                          NHTSA-endorsed Boston University study concluded that 500 to 600 fewer
                                          fatal crashes would occur each year if all states adopted .08 BAC laws, this
                                          study has been criticized for, among other reasons, its method of
                                          comparing states; and a recent NHTSA study characterized the earlier
                                          study’s conclusion as “unwarranted.” The fourth study reported mixed



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                         results. Therefore, these studies did not provide conclusive evidence that
                         .08 BAC laws by themselves have resulted in reductions in drunk driving
                         crashes and fatalities. A task force of the New Jersey State Senate
                         examined this evidence and, in a report issued in December 1998, reached
                         a similar conclusion.8

The California Studies   NHTSA  has cited California’s experience as evidence of the effectiveness of
                         .08 BAC laws. For example, in a publication promoting the need for .08 BAC
                         laws, NHTSA stated that “alcohol-related fatalities significantly decreased
                         after the state’s BAC limit was lowered to .08 in 1990.” In another
                         publication, it said “California’s .08 law was analyzed by NHTSA, [and] . . .
                         the state experienced a 12% reduction in alcohol-related fatalities,
                         although some of this can be credited to the new administrative license
                         revocation law.”

                         While NHTSA’s 1991 study by Research and Evaluation Associates (see
                         table 1) did find a 12-percent decline in alcohol-related fatalities after the
                         .08 BAC law took effect, the study had important limitations. For example,
                         the authors had available to them only 1 year of data for the period after
                         the law went into effect, an unusually short period of time to analyze
                         trends, and the authors acknowledged this limitation. California also had a
                         license revocation law—under which a person deemed to be driving under
                         the influence has his or her driving privileges suspended or revoked—take
                         effect 6 months after the .08 BAC law. Although the authors concluded that
                         this law had no effect, they stated that they were unable to accurately
                         account for the separate effects of the two laws.

                         A more comprehensive, methodologically sound study of California was
                         released by the state’s Department of Motor Vehicles in 1995. In contrast
                         to the 1991 review, this study was based on 4 years of data after the law
                         became effective and found mixed results. The study concluded that the
                         .08 BAC law was not associated with any statistically significant reductions
                         in crashes resulting in fatalities or serious injuries in which drivers were
                         reported to have been drinking, but that reductions did occur in accidents
                         that took place during hours in which alcohol involvement is probable,
                         such as nighttime crashes between 2 and 3 a.m. The study found

                         8
                          State of New Jersey, Senate Task Force on Alcohol-Related Motor Vehicle Accidents and Fatalities,
                         Dec. 11, 1998. Created by the leaders of the New Jersey State Senate, the task force was composed of
                         elected officials and representatives from the state’s judicial, medical, academic, and law enforcement
                         communities. The task force was charged with, among other things, evaluating the available studies,
                         and determining whether reducing the BAC limit to .08 would reduce the number of alcohol-related
                         accidents and fatalities in New Jersey. The task force concluded that “the impact of laws that reduce
                         the per se BAC level from .10 to .08, in isolation, is inconclusive” and that the effect of public
                         education and awareness campaigns and license revocation laws “can be greater than changing the
                         legal BAC.”



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                                  reductions associated with the state’s license revocation law—a 9 to
                                  13 percent decline in crashes resulting in fatalities or serious injuries in
                                  which drivers were reported to have been drinking. However, given the
                                  6-month time period separating the effective dates of the two laws, the
                                  authors concluded that .08 BAC and license revocation laws most likely
                                  worked together to lower fatalities.

                                  Although the 1995 study was more comprehensive than the 1991 study,
                                  NHTSA’s public statements and literature often quote the 12-percent
                                  reduction cited in the 1991 study and rarely refer to the 1995 study.
                                  California continued to experience a decline in alcohol-related fatalities
                                  through the 1990s—from 47 percent of fatalities in 1991 to 36 percent in
                                  1997. California traffic safety and law enforcement officials believe that
                                  this progress is attributable to the combination of stronger laws, a
                                  sustained public information campaign, and vigorous enforcement.

The Boston University Study       A 1996 study by researchers from the Boston University School of Public
                                  Health published in the American Journal of Public Health compared the
                                  first five states to adopt .08 BAC laws with five “nearby” states that
                                  retained .10 BAC laws. It found a 16 percent greater decline in the
                                  proportion of alcohol-related fatalities among drivers in the states
                                  adopting the lower limit and concluded that if all states adopted .08 BAC
                                  laws, 500 to 600 fewer fatal crashes would occur annually. These study
                                  results were endorsed by NHTSA and often cited in the agency’s literature
                                  and public statements. President Clinton cited the study in a March 1998
                                  statement and said “. . . if all states lower their BAC to .08, it will result in
                                  600 fewer alcohol-related deaths each year.”

                                  However, this study has been criticized by many traffic safety experts both
                                  inside and outside of NHTSA and has methodological limitations that call its
                                  results into question. For example:

                              •   Many traffic safety experts question this study’s method of comparing one
                                  state to another. The study does not explain the criteria used to select the
                                  comparison states. Using one state as a control to assess the impact of a
                                  new law in another state assumes that all other conditions are held equal
                                  except for the introduction of the law. One critic noted, for example, that
                                  one of the states with a .08 BAC law employs random roadside sobriety
                                  checkpoints and was compared to a state with a .10 BAC law that prohibits
                                  the practice. Changing the selection of comparison states can dramatically
                                  change this study’s results. According to NHTSA, while other traffic safety
                                  studies have made single state comparisons, it is best to compare one state



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                        to several or to the rest of the nation.

                    •   Three of the five states had license revocation laws take effect within 10
                        months of their .08 BAC laws. This study made no effort to separately
                        analyze the relative contribution of the two types of laws to any
                        subsequent decline in fatal motor vehicle crashes in those three states.
                        Thus, in at least three states, the authors’ findings could as easily apply to
                        the license revocation law as the .08 BAC law. The authors acknowledged
                        this limitation, but it is rarely cited in NHTSA’s literature and public
                        statements endorsing this study and its findings.

                    •   The study’s conclusion that 500 to 600 fewer fatal crashes would occur
                        annually if all states had .08 BAC laws is unfounded. The study does not
                        explain how this estimate was derived or how the reduction could be
                        credited to .08 BAC laws since the .08 BAC and license revocation laws went
                        into effect within 10 months of each other in three of the five states. The
                        authors told us that the estimate assumed that all states without .08 BAC
                        laws would experience a reduction of up to 10 percent in alcohol-related
                        crashes after enacting the laws. However, the study provides no basis for
                        assuming that reductions of that magnitude would occur. Even this
                        particular study found that while three of the five states experienced
                        reductions greater than their comparison state, two of the five did not.
                        NHTSA’s April 1999 study of the effect of .08 BAC laws in 11 states (see table
                        1) characterized this conclusion as “unwarranted.”

NHTSA Staff Study       In 1994, NHTSA staff conducted a study that examined FARS data in the first
                        five states that enacted .08 BAC laws (see table 1). NHTSA has often cited
                        this study as evidence of the effectiveness of .08 BAC laws. For example, a
                        December 1997 publication with the National Safety Council said,
                        “. . . significant reductions in alcohol-related fatal crashes were found in 4
                        out of the 5 states ranging from 4% to 40%. . . .”

                        The staff study examined 6 measures of alcohol involvement, ranging from
                        fatal crashes involving drivers with high BACs to single-vehicle crashes late
                        at night, in each of the five states (for a total of 30 measures) and found
                        statistically significant decreases in 9 of the 30 measures. The study also
                        had several important limitations, which the authors acknowledged. For
                        example, as with the Boston University study, the staff study made no
                        effort to separately account for the relative contributions of .08 BAC laws
                        and license revocation laws in the three states that enacted them within a
                        short period. The staff study cautioned that the results were preliminary
                        and that they pointed to the need for further research. NHTSA’s public



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                          statements, however, were more definitive—conveying, for example, the
                          impression that fatal crashes involving alcohol went down 40 percent in
                          one of the five states. However, the 40-percent figure refers to only one of
                          the six measures in Vermont, a state that experiences fairly significant
                          year-to-year variations in fatal crashes. One of the authors told us he
                          viewed the results as indicative of positive but not clear results.


Recent Studies Are More   On April 28, 1999, NHTSA released three studies that it sponsored (see table
Comprehensive, but        1). These studies are more comprehensive than the earlier studies and
Results Are Mixed         show many positive results but fall short of conclusively establishing that
                          .08 BAC laws by themselves have resulted in reductions in alcohol related
                          fatalities. For example, during the early 1990s, when the involvement of
                          alcohol in traffic fatalities declined from around 50 percent to nearly
                          40 percent—a trend in states with both .08 BAC and .10 BAC laws—eight
                          states’ .08 BAC laws became effective, and the recent studies disagree on
                          the degree to which .08 BAC laws played a role. Two of the studies reached
                          different conclusions about the effect of one state’s .08 BAC law—one
                          concluded that the law brought about reductions in drunk driving deaths
                          in North Carolina, while another concluded that the state’s reductions
                          occurred as the result of a long-term trend that began before the law was
                          enacted. In a statement releasing the three studies, NHTSA credited the
                          nation’s progress in reducing drunk driving to a combination of strict state
                          laws and tougher enforcement and stated that “these three studies
                          provide additional support for the premise that .08 BAC laws help to reduce
                          alcohol-related fatalities, particularly when they are implemented in
                          conjunction with other impaired driving laws and programs.”

Eleven-State Study        An April 1999 NHTSA study of 11 states with .08 BAC laws (see table
                          1) assessed whether the states experienced statistically significant
                          reductions in three measures of alcohol involvement in crashes after the
                          law took effect: (1) the number of fatalities in crashes in which any
                          alcohol was involved, (2) the number of fatalities in crashes where drivers
                          had a BAC of .10 or greater (“high BAC”), and (3) the proportion of
                          fatalities involving “high BAC” drivers to fatalities involving sober
                          drivers. The study performed a similar analysis for license revocation laws
                          and also modeled and controlled for any preexisting long-term declining
                          trends these states may have been experiencing when their .08 BAC laws
                          went into effect. The study found that 5 of the 11 states had reductions in
                          at least one measure and that 2 of the 11 states had reductions in all three
                          measures. Table 2 summarizes the states and measures for which the




                          Page 16                  GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
                                          B-280883




                                          study found statistically significant reductions after .08 BAC laws became
                                          effective.


Table 2: Results of the 11-State Study of .08 BAC Laws
                                                                       Statistically significant reduction occurred in
                                                                                                                  Proportion of
                          Year .08                                                                                fatalities involving
                          BAC law                                                                                 “high BAC” drivers
                          became                     Alcohol-related               Fatalities involving           to those involving
State                     effective                  fatalities                    “high BAC” drivers             sober drivers
Utah                      1983                       No                            No                             No
Oregon                    1983                       No                            No                             No
Maine                     1988                       No                            No                             No
California                1990                       No                            No                             No
Vermont                   1991                       Yes                           Yes                            Yes
Kansas                    1993                       No                            No                             Yes
North Carolina            1993                       No                            No                             Yes
Florida                   1994                       Yes                           Yes                            Yes
New Hampshire             1994                       No                            No                             No
New Mexico                1994                       No                            No                             Yes
Virginia                  1994                       No                            No                             No
Total                                                2 of 11                       2 of 11                        5 of 11
                                          Note: “Yes” indicates a statistically significant reduction after the .08 BAC law became effective.
                                          “No” indicates no statistically significant reduction.



                                          Reductions in all three measures of fatalities involving alcohol occurred in
                                          Florida and Vermont. Although alcohol involvement in fatal crashes began
                                          to decline in Florida before the .08 BAC law was enacted, it continued to do
                                          so after the law went into effect on January 1, 1994. According to FARS, the
                                          number of alcohol-related traffic deaths in Florida declined in 1994 by
                                          nearly 10 percent, while the proportion of fatalities involving alcohol fell
                                          from 44 to 39 percent—in 1997 it stood at around 34 percent. While the
                                          study noted that Vermont has experienced fluctuations in its fatal crash
                                          rates, it found that after Vermont’s .08 BAC law took effect, it also
                                          experienced statistically significant reductions in both the number of
                                          fatalities involving alcohol and the proportion of fatalities involving drivers
                                          with high BACs to those involving sober drivers. In this study, Vermont was
                                          the only state of the first five states to enact .08 BAC laws that showed any
                                          reductions in alcohol-related fatalities associated with .08 BAC laws.




                                          Page 17                           GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
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Three other states that enacted .08 BAC laws in 1993 and 1994—North
Carolina, New Mexico, and Kansas—experienced statistically significant
reductions in the proportion of fatalities involving drivers with high BACs
to those involving sober drivers. According to one of the authors, this
proportion is the most accurate indicator of the study’s three
measures—the study noted that if fatalities involving sober drivers decline
along with alcohol-related fatalities, then some broader cause other than
alcohol legislation is affecting all traffic fatalities. However, if the .08 BAC
law operates as expected, alcohol-related deaths will decline while deaths
involving sober drivers remain unaffected. In Kansas, the proportion of
alcohol involvement declined because fatalities involving sober drivers
increased while alcohol-related fatalities remained relatively stable, and in
North Carolina, fatalities involving sober drivers increased markedly while
fatalities involving drivers with high and low BACs continued their
preexisting downward trend. The author stated that without the .08 BAC
legislation, alcohol-related fatalities would have been expected to increase
along with fatalities involving sober drivers.

In two states where no statistically significant reductions occurred after
.08 BAC laws became effective in any category—California and
Virginia—the study found that the .08 BAC laws were effective when paired
with the states’ license revocation laws. In both cases, the license
revocation laws went into effect after the .08 BAC laws, and the study found
that the reductions did not begin until the license revocation laws were in
force.

Finally, the study found no statistically significant reductions in four
states. Utah experienced no noticeable change in fatalities involving
alcohol after enacting both its .08 BAC and license revocation laws in 1983.
The authors noted that the rate of alcohol involvement in fatal crashes in
Utah was substantially lower than the national average and that further
reductions would have been difficult. Fatalities involving alcohol in
Oregon showed little change after the .08 BAC law went into effect in
1983—the most dramatic change occurred over 6 years after the law’s
implementation. Maine experienced no significant reductions in
alcohol-related fatalities after its .08 BAC law was implemented in 1988.
New Hampshire experienced a decline in alcohol-related fatalities 2 years
before its .08 BAC law went into effect in 1993 but saw no significant
decline in fatalities associated with the .08 BAC law.

The study was careful to not draw a causal relationship between the
reductions it found and the passage of .08 BAC laws by themselves. Rather,



Page 18                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
                                   B-280883




                                   it concluded that .08 BAC laws added to the impact that enforcement;
                                   public information; and legislative activities, particularly license
                                   revocation laws, were having. In addition to the two states where .08 BAC
                                   and license revocation laws were found to be effective in combination, the
                                   study noted that the five states with .08 BAC laws that showed reductions
                                   already had license revocation laws in place. One of the authors told us
                                   that this suggested that the .08 BAC laws had the effect of expanding the
                                   scope of the license revocation laws to a new portion of the driving public.

University of North Carolina       A NHTSA-sponsored study by the University of North Carolina concluded, in
Study                              contrast to the 11-state study, that the .08 BAC law in North Carolina had
                                   little clear effect. The study examined alcohol-related crashes and crashes
                                   involving drivers with BACs greater than .10 from 1991 through 1995;
                                   compared fatalities among drivers with BACs greater than .10 in North
                                   Carolina with such fatalities in 11 other states; and compared six measures
                                   of alcohol involvement in North Carolina and 37 states that did not have
                                   .08 BAC laws at that time. The study controlled for and commented on
                                   external factors that could confound the results, such as the state’s
                                   sobriety checkpoints, enforcement, and media coverage. The study found
                                   the following:

                               •   No statistically significant decrease in alcohol-related crashes after
                                   passage of North Carolina’s .08 BAC law in three direct and two “proxy”
                                   measures.9

                               •   A continual decline in the proportion of fatally injured drivers with BACs
                                   equal to or greater than .10 but no abrupt change in fatalities that could be
                                   attributed to the .08 BAC law.

                               •   Decreases in alcohol-related crashes in North Carolina and in the 11 other
                                   states studied. While North Carolina’s decreases were greater, the study
                                   concluded that no specific effects could be attributed to the .08 BAC law.

                               •   No statistically significant difference between North Carolina and 37 states
                                   without .08 BAC laws in four of the six measures. While reductions in
                                   police-reported and estimated instances of alcohol involvement were
                                   found to be statistically significant, these reductions happened 18 months
                                   before North Carolina lowered its BAC limit. The authors attributed these
                                   decreases, in part, to increased enforcement.


                                   9
                                    Direct measures are actual observations, such as police reports of alcohol involvement in crashes,
                                   whereas proxy measures are not actual observations, but categories in which the involvement of
                                   alcohol is considered probable, such as nighttime crashes between 2 and 3 a.m.



                                   Page 19                          GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
                 B-280883




                 The study concluded that the .08 BAC law had little clear effect on
                 alcohol-related fatalities in North Carolina, and that a downward trend
                 was already occurring before North Carolina enacted its .08 BAC law and
                 that this trend was not affected by the law. The authors offered several
                 possible explanations, including that (1) the effects of the .08 BAC laws
                 were obscured by a broader change in drinking-driving behavior that was
                 already occurring; (2) North Carolina had made substantial progress
                 combating drunk driving and that the remaining drinking and driving
                 population in North Carolina was simply not responsive to the lower BAC
                 law; and (3) .08 BAC laws are not effective in measurably affecting the
                 behavior of drinking drivers.


50-State Study   The third April 1999 NHTSA study did a complex regression analysis
                 assessing the effect of three drunk driving laws, including .08 BAC laws.10 It
                 evaluated .08 BAC laws by comparing two groups—states with .08 BAC laws
                 with states with .10 BAC laws, before and after the laws were passed. The
                 study examined quarterly FARS data for all 50 states and Washington, D.C.
                 from 1982 through 1997 and tested for reductions in the involvement of
                 (1) “low BAC” drivers (.01 BAC through .09 BAC) and (2) “high BAC”
                 drivers (.10 BAC and above) in fatal crashes. The study was more
                 comprehensive than the prior multistate studies, having controlled for the
                 effects of factors such as the number of licensed drivers, vehicle miles
                 traveled, per capita beer consumption, unemployment rates, urban/rural
                 composition, season, safety belt laws, and existing downward trends in
                 alcohol-related fatal crashes. This study concluded that states that enacted
                 .08 BAC laws experienced an 8-percent reduction in the involvement of
                 drivers with both high and low BACs when compared with the involvement
                 of sober drivers. The study estimated that 274 lives have been saved in the
                 states that enacted .08 BAC laws and that 590 lives could be saved annually
                 if all states enacted .08 BAC laws.

                 While more comprehensive than other studies, the study used a method to
                 calculate the 8-percent reduction that is different, and thus not directly
                 comparable, to those for fatality estimates reported in other studies and
                 publications. In particular, this method can produce a numerical effect
                 that is larger than other methods. In the past, NHTSA’s statistics and other
                 studies measured differences either (1) in the number of alcohol-related
                 fatalities or the number of drivers reported to have been using alcohol
                 (termed “alcohol-involved” drivers) or (2) in the proportion of such

                 10
                   Regression analysis is a statistical technique used to describe and analyze relationships between a
                 dependent variable (e.g. fatal crashes involving alcohol) and one or more independent variables (e.g.
                 .08 BAC and license revocation laws).



                 Page 20                          GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
                                     B-280883




                                     fatalities or drivers as a percentage of all fatalities or drivers. The 50-state
                                     study’s 8-percent estimate is the change in the ratio of alcohol-involved
                                     drivers to sober drivers who are in fatal crashes. While this is not an
                                     inappropriate way to measure differences in crashes and fatalities, this
                                     method can increase the size of the effect because, rather than comparing
                                     fatalities or drivers involving alcohol to all fatalities or drivers, it compares
                                     the number of alcohol-involved drivers to just the number of sober drivers.
                                     This method produced a larger effect in this study because, since 1982, of
                                     the drivers involved in fatal crashes, the number reported to have been
                                     using alcohol has dramatically declined (by around 39 percent), while the
                                     number reported to have been sober has substantially increased (by
                                     around 25 percent). While the 11-state study also measured this ratio, that
                                     study did not report a numerical effect.

                                     Table 3 illustrates the difference between these methods of portraying
                                     traffic statistics using NHTSA’s FARS data on drivers involved in fatal crashes
                                     between 1995 and 1997. As the table shows, while the number of
                                     alcohol-involved drivers declined by about 6 percent, the ratio of such
                                     drivers to sober drivers declined by 9 percent.

Table 3: Drivers Involved in Fatal
Crashes, 1995-97                                                                            1995          1997    Difference
                                     Alcohol-involved drivers                             14,269        13,393           (6.1%)
                                     Sober drivers                                        41,895        43,209            3.1%
                                     All drivers                                          56,164        56,602            0.8%
                                     Ratio of alcohol-involved drivers to sober
                                     drivers                                                  34%           31%            (9%)
                                     Source: GAO’s analysis of FARS data.



                                     Another reason why this study’s results cannot be directly compared to
                                     other studies’ is because it did not include data for drivers under 21. In
                                     1997, drivers under 21 accounted for around 14 percent of the drivers in
                                     fatal crashes and about 12 percent of the drivers in fatal crashes involving
                                     alcohol. According to the authors, drivers under 21 were excluded from
                                     the analysis because other laws affect these drivers, such as minimum
                                     drinking age and “zero tolerance” BAC laws, and thus the primary effect of
                                     .08 BAC legislation would be expected to be on the population over 21
                                     years old. While this argument may have merit, other arguments exist for
                                     including this population. First, NHTSA has stated that .08 BAC laws have a
                                     general deterrent effect on drinking and driving among all drivers. Also,
                                     young drivers violating .08 BAC laws have been prosecuted under those




                                     Page 21                        GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
              B-280883




              laws without regard to age, suggesting that these laws do not affect only
              adults. For example, in California, 13,067 drivers under 21 were convicted
              under the state’s .08 BAC law in 1997, compared with 11,517 drivers under
              21 convicted under the state’s “zero tolerance” BAC law. Finally, with the
              exception of the 1994 NHTSA staff study, all other studies of the effect of .08
              BAC laws, including the recent 11-state and North Carolina studies, have
              included persons under 21 in their analyses.

              Including persons under 21 years old would have changed these study
              results. In particular, the study would have found no statistically
              significant reductions associated with .08 BAC laws for drivers at low BAC
              levels. The findings regarding drivers at high BAC levels—a group that
              contains over 3 times as many drivers—would have remained substantially
              unchanged.

              The study warns that “it is important to interpret estimates of lives saved
              due to any single law with considerable caution.” In particular, as the
              study notes, factors such as public education, enforcement, and changes in
              societal norms and attitudes toward alcohol have produced long-term
              reductions in drunk driving deaths over many years. This study did more
              to control for extraneous factors than any of the other multistate studies,
              but this is inherently difficult to do, and in this case the authors estimate
              that 50 to 60 percent of the reductions in alcohol-related fatalities are
              explained by the laws it reviewed and the other factors it considered, a
              moderate level for statistical analyses of this type. Because of the
              uncertainties, the study’s estimate of lives saved is also expressed as a
              range—and the number of lives saved in states with .08 BAC laws could
              have been as few as 88 or as many as 472.11 Similarly, if the states without
              .08 BAC laws enacted them and experienced reductions comparable to
              those found in the study, the number of lives saved annually was projected
              to be as few as 200 or as many as 958. While the study reported results for
              the three laws it reviewed, including .08 BAC laws, the study also concluded
              that “the attribution of savings to any single law should be made with
              caution since each new law builds to some extent on existing legislation
              and on other ongoing trends and activities.”


              While indications are that .08 BAC laws in combination with other drunk
Conclusions   driving laws as well as sustained public education and information efforts
              and strong enforcement can be effective, the evidence does not

              11
                The study made range estimates at the 95 percent confidence level, meaning that one would expect
              these results to occur in 95 out of 100 cases.



              Page 22                         GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
                     B-280883




                     conclusively establish that .08 BAC laws by themselves result in reductions
                     in the number and severity of crashes involving alcohol. Until recently,
                     limited published evidence existed on the effectiveness of .08 BAC laws,
                     and NHTSA’s position—that this evidence was conclusive—was overstated.
                     In 1999, more comprehensive studies have been published that show many
                     positive results, and NHTSA’s characterization of the results has been more
                     balanced. Nevertheless, these studies fall short of providing conclusive
                     evidence that .08 BAC laws by themselves have been responsible for
                     reductions in fatal crashes.

                     Because a state enacting a .08 BAC law may or may not see a decline in
                     alcohol-related fatalities, it is difficult to accurately predict how many lives
                     would be saved if all states passed .08 BAC laws. The effect of a .08 BAC law
                     depends on a number of factors, including the degree to which the law is
                     publicized; how well it is enforced; other drunk driving laws in effect; and
                     the unique culture of each state, particularly public attitudes concerning
                     alcohol.

                     As drunk driving continues to claim the lives of thousands of Americans
                     each year, governments at all levels seek solutions. Many states are
                     considering enacting .08 BAC laws, and the Congress is considering
                     requiring all states to enact these laws. Although a strong causal link
                     between .08 BAC laws by themselves and reductions in traffic fatalities is
                     absent, other evidence, including medical evidence on impairment, should
                     be considered when evaluating the effectiveness of .08 BAC laws. A .08 BAC
                     law can be an important component of a state’s overall highway safety
                     program, but a .08 BAC law alone is not a “silver bullet.” Highway safety
                     research shows that the best countermeasure against drunk driving is a
                     combination of laws, sustained public education, and vigorous
                     enforcement.


                     DOT provided comments on a draft of this report (see app. I). The
Agency Comments      Department generally agreed with the information presented in the report.
and Our Evaluation   DOT reiterated its long-standing commitment to a systems approach for
                     combating drunk driving and stated that while no individual component,
                     including .08 BAC laws, is effective in isolation, the overall evidence
                     supports the effectiveness of .08 BAC laws. DOT stated that the four original
                     studies provided positive, if not conclusive, results and formed a
                     reasonable basis for supporting .08 BAC laws. The three recent studies
                     added to this body of evidence, including the North Carolina study, which,
                     while finding little clear effect of the state’s .08 BAC law, did find



                     Page 23                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
              B-280883




              reductions. Consequently, DOT concluded that significant reductions have
              been found in most states, that consistent evidence exists that .08 BAC
              laws, at a minimum, add to the effectiveness of laws and activities already
              in place, and that a persuasive body of evidence is now available to
              support the Department’s position on .08 BAC laws.

              Overall, we believe that DOT’s assessment of the effectiveness of .08 BAC
              laws is fairly consistent with our own. We agree with DOT on the
              importance of a systems approach to combating drunk driving; we have
              noted examples in this report such as the state of California, where .08 BAC
              laws were not effective until other complementary measures were put into
              place. DOT did not disagree with our discussion concerning the limitations
              and methodological concerns for three of the first four studies or with our
              assessment that recent studies reach different conclusions about the
              effectiveness of .08 BAC laws; we believe those study results must be
              viewed in the context of their limitations and conclusions. Although DOT
              stated that studies showed significant reductions in most states, the
              11-state study demonstrated reductions associated with .08 BAC laws in a
              minority of states (5 of 11) and a minority of the measures (9 of 33) it
              studied. In addition, many of the results DOT cited as consistent evidence
              supporting its position were reductions that study authors determined not
              to be statistically significant—thus, no conclusions on the effectiveness of
              .08 BAC laws can be drawn from them. Although we characterize the
              strength of the study results differently, we and DOT reach essentially the
              same conclusion regarding the effectiveness of .08 BAC laws, both by
              themselves and in combination with other measures.


              To determine the effect of .08 BAC laws on the number and severity of
Scope and     alcohol-related crashes, we analyzed the body of research published
Methodology   between 1991 and 1999. Of the seven studies, five were published by NHTSA,
              one by the state of California, and one by the American Journal of Public
              Health. We reviewed the studies’ methodologies, findings, and conclusions
              and met with study authors at NHTSA, the Pacific Institute for Research and
              Evaluation, the California Department of Motor Vehicles, and Boston
              University’s School of Public Health. We also discussed the studies and
              traffic safety issues with NHTSA officials in Washington, D.C., Boston,
              Massachusetts, and San Francisco, California; officials of the American
              Automobile Association, the Insurance Institute for Highway Safety, the
              National Sheriffs Association, Mothers Against Drunk Driving, the
              American Beverage Institute, the National Restaurant Association; and
              state traffic safety and law enforcement officials in California.



              Page 24                  GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
B-280883




The scope of our study was limited to the effect of .08 BAC laws on the
number and severity of alcohol-related crashes. We did not review several
other arguments raised by both proponents and opponents of .08 BAC laws;
for example, while we describe the medical evidence on impairment, we
did not evaluate that evidence. In addition, our ability to review the
severity of alcohol-related crashes was limited by the fact that the FARS
database—used entirely by five of the seven studies and in part by a
sixth—includes only fatal crashes. The .08 BAC laws reviewed may have
had a greater or lesser effect on nonfatal crashes than it did on fatal
crashes. Finally, section 2008 of the Transportation Equity Act for the 21st
Century required us to review the effect of .02 BAC laws for drivers under
21 in reducing the number and severity of alcohol-related crashes. As
agreed with your staff, we will not address those laws as all 50 states and
the District of Columbia now have laws establishing BAC levels of .02 or
less for drivers under 21 years of age.

We performed our work from August 1998 through April 1999 in
accordance with generally accepted government auditing standards.


We will send copies of this report to cognizant congressional committees;
the Secretary of Transportation; and the Administrator, National Highway
Traffic Safety Administration. We will make copies available to others
upon request. If you have any questions regarding this report, please
contact me at (202) 512-3650 or Ronald Stouffer at (202) 512-4416. Key
contributors are listed in appendix II.

Sincerely yours,




Phyllis F. Scheinberg
Associate Director,
  Transportation Issues




Page 25                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
Appendix I

Comments From the Department of
Transportation




             Page 26   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
Appendix I
Comments From the Department of
Transportation




Page 27                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
Appendix I
Comments From the Department of
Transportation




Page 28                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
Appendix I
Comments From the Department of
Transportation




Page 29                   GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
Appendix II

GAO Contacts and Staff Acknowledgments


                  Phyllis F. Scheinberg, (202) 512-3650
GAO Contacts      Ronald E. Stouffer, (202) 512-4416


                  In addition to those named above, Steve Cohen, Amy Gleason Carroll, Sara
Acknowledgments   Ann Moessbauer, Mitchell B. Karpman, and Allan Rogers made key
                  contributions to this report.




(348125)          Page 30                 GAO/RCED-99-179 Highway Safety and .08 Blood Alcohol Laws
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