PER SE ALCOHOL 0.05 BAC
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Discussion: Changing Washington’s per se blood alcohol
concentration (BAC) limit from .08% to .05% BAC
Contact: Mark McKechnie, Director of External Relations, Washington Traffic Safety Commission
(360) 725-9889 | mmckechnie@wtsc.wa.gov
Key Data Points
• More than half of fatal crashes in Washington involve driver impairment by drugs
and/or alcohol, including at least 32 percent of fatal crashes that involve alcohol positive
drivers. (2017-2021)
• Drivers experience cognitive, behavioral, and physical impairment with a blood alcohol
concentration (BAC) level of 0.05.
• Crash risk increases substantially for drivers with a BAC of .05-.079. The risk of a single-
vehicle fatal collision is at least seven times greater compared to a driver with a 0.00
BAC (no alcohol in their system).
• Impaired drivers are more likely to speed, less able to react and control their vehicles,
and less likely to wear seat belts.
• Utah saw significant decreases in fatal crashes (-19.8 percent), serious injury crashes
(-10.8 percent), and all crashes (-9.6 percent) in the 12 months following the
implementation of its 0.05 BAC law.
• Utah also saw fewer incidences of crashes involving alcohol impairment across a range
of BAC levels, from a 14.7 percent reduction of crashes involving drivers with a 0.05 BAC
or above, to a 9.1 percent reduction in crashes involving drivers with a 0.15 BAC or
higher.
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Introduction
Driver impairment by alcohol or drugs is involved in more than half of all fatal crashes in
Washington. Sixty percent of the fatal crashes involving a driver under the influence of alcohol
occur in just six counties. Here are the percentage of crashes involving a driver positive for
alcohol in these counties over a 5-year period:
Location
Total Fatal crashes, 2017-2021
1
Percent involving alcohol positive
drivers
King
548
Pierce
327
Snohomish
194
Spokane
209
Yakima
178
Clark
145
Washington
total
2,672
There were 2,672 fatal crashes involving 4,114 motor vehicle drivers in Washington from 2017-
2021. Among drivers involved in fatal crashes, 867, or one in five, drivers were determined to
have consumed alcohol prior to the crash. These crashes are preventable, and multiple
strategies will be required to reduce and eliminate crashes involving impaired driving. Policies
and practices that prevent drivers from driving
impaired in the first place will have the greatest
impact in preventing serious and fatal crashes.
Every state and most countries set legal limits on
driving while impaired. In addition to the
behavioral, cognitive, and physical symptoms of
impairment, criminal laws often set a BAC limit,
over which the person is presumed to be too
impaired to drive. These are commonly called “per
se” limits. They are part of an overall strategy to
prevent impaired driving from occurring or to
intervene when it is occurring.
Washington lowered the BAC limit for alcohol most recently in 1999, when the per se BAC level
was lowered from 0.10 to 0.08. Legislation to lower the DUI per se alcohol limit from 0.08 to
1
WTSC Fatal Crash Dashboards, accessed May 2022, https://wtsc.wa.gov/research-data/dashboards/
The National Transportation
Safety Board (NTSB) has urged
all 50 states to adopt a
DUI per se BAC standard
of .05 percent or less.
PER SE ALCOHOL 0.05 BAC
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0.05 has been introduced twice previously: HB 1874 in 2017 and SB 5982 in 2022. The National
Transportation Safety Board continues to recommend that all 50 states lower the per se BAC
laws to 0.05 or less.
Utah has already enacted legislation to lower its per se limit to 0.05. That law took effect in
December 2018, and research on its impact is very informative. It was effective at reducing the
incidence of alcohol-impaired driving, and Utah saw significant decreases in all crash types
following the enactment and implementation of the law.
This paper contains information about the issue for consideration by our commissioners and
partners.
BAC Impact
The impact of a BAC limit extends far beyond enforcement. These limits remind people of the
risks of impaired driving, and many people modify their behavior as a result. Thus, the impact of
the 0.05 BAC limit provides a broad deterrent, rather than significantly increasing enforcement
or prosecution. Washington created the offense of driving while under the influence of
intoxicating liquor or any drug in 1979. The new law included a per se BAC level for DUI at 0.10.
Based upon research that drivers are impaired well before they reach a 0.10 BAC, Washington
lowered its limit to 0.08 in 1999. After the BAC was lowered to 0.08 in 1999, drivers in fatal
crashes with very high BACs (greater than .15) declined by almost 20 percent, while drivers with
no alcohol increased almost 10 percent (1994-1998, compared to 2009-2013). During this same
time period, fatalities involving a drinking driver (any BAC) declined 38 percent.
The problem with the current 0.08 BAC limit is that it may convey a message to drivers that
they are not impaired with a BAC of 0.05- 0.079. This is not the case.
The National Highway Traffic Safety Administration (NHTSA) and others have recommended for
more than a decade that states lower BAC limits further to 0.05. The chart below compares the
physical, behavioral, and cognitive impacts on people at the historical and proposed levels and
their typical impacts on driving.
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It shows that impaired judgement and release of inhibition
result from alcohol impairment at 0.05 BAC. Thus, individuals have already begun to lose the
ability to judge whether or not they should drive at that point of intoxication. This means it is
necessary for individuals to make the decision not to consume alcohol or to make plans not to
drive before they reach this level of alcohol in their bodies.
2
Centers for Disease Control: “Impaired Driving: Get the Facts”
PER SE ALCOHOL 0.05 BAC
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BAC (%)
Typical Effects
Predictable Effects on Driving
0.05
Proposed
• Exaggerated behavior
• May have loss of small-muscle control
(e.g., focusing your eyes)
• Impaired judgment
• Usually good feeling
• Lowered alertness
• Release of inhibition
• Reduced coordination
• Reduced ability to track moving objects
• Difficulty steering
• Reduced response to emergency driving
situations
0.08
(Est.
1999)
Impacts listed above, plus:
• Muscle coordination becomes poor
(e.g., balance, speech, vision, reaction
time, and hearing)
• Harder to detect danger
• Judgment, self-control, reasoning, and
memory are impaired
Impacts listed above, plus:
• Impaired concentration
• Short-term memory loss
• Diminished speed control
• Reduced information processing
capability (e.g., signal detection, visual
search)
• Impaired perception
0.10
(Est.
1979)
Impacts listed above, plus:
• Clear deterioration of reaction time
and control
• Slurred speech, poor coordination,
and slowed thinking
Impacts listed above, plus:
• Reduced ability to maintain lane
position and brake appropriately
Washington Data
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Among the 2,877 traffic fatalities in 2017-2021, 32 percent involved a driver positive for
alcohol. This may be an under-count of drivers under the influence of alcohol because,
unfortunately, 49 percent of drivers involved in fatal crashes were not tested for drugs or
alcohol during that period. Only 31 percent of those who were tested did not test positive for
alcohol, cannabis, or other drugs that could be impairing.
There were 326 drivers involved in fatal crashes who were found through toxicology testing to
be positive for alcohol and no other substances. These included 48 (15 percent) drivers with
BAC levels below the current per se limit of 0.08. Among the 410 drivers positive for alcohol
along with other substances, 78 (19 percent) of those had BAC levels below 0.08.
Among drivers involved in fatal crashes who tested positive for cannabinoids, the majority (281
drivers, 54 percent) also tested positive for alcohol. Among all drivers in fatal crashes positive
3
WTSC Fatal Crash Dashboards, accessed May 2022, https://wtsc.wa.gov/research-data/dashboards/
PER SE ALCOHOL 0.05 BAC
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for drugs or alcohol, nearly 40 percent were speeding at the time of the fatal crash, and nearly
one-third were unrestrained. These are two additional risk factors that significantly increase the
likelihood of fatality. Twenty-seven percent (27 percent) of these drivers had a history of one or
more previous crashes.
Utah’s 0.05 BAC Per Se Law
The National Highway Traffic Safety Administration (NHTSA) published an evaluation of Utah’s
law change in 2022.
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Legislation to lower the per se BAC limit to 0.05 in Utah was passed in
2017. Changes in the law were publicized, but law enforcement agencies did not substantially
change enforcement strategies related to DUI as a result of this change. Law enforcement has
and will continue to rely upon behavioral signs of impairment to determine whether to stop a
driver. Driver BAC levels are only determined after a traffic stop or a crash occurs. Researchers
looked at the fatal crash data from the first full year that the change was in effect, 2019, and
compared it to 2016 data. The NHTSA findings on the overall impacts of the law are significant:
• 22.1 percent of drinkers reported changing their behaviors as a result of the law (e.g.,
more people avoided driving after consuming alcohol), however, alcohol sales, tax
revenues, and tourism remained largely unchanged
• The rate of fatal crashes (incident rate) per million vehicle miles travelled (VMT) fell 19.8
percent
• The rate of fatalities (deaths of people involved in crash incidents) per million VMT fell
18.3 percent.
In addition to the significant reductions in fatal crashes, the NHTSA study also found that
crashes and reported incidents involving impaired driving fell as well (calculated based upon the
rates per million VMT):
• Total crashes decreased 9.6 percent
• Injury crashes fell 10.8 percent
• Crashes involving drivers with BAC levels at or above the 0.05 per se limit decreased
14.7 percent
• Crashes involving drivers with BAC levels at or above the old limit of 0.08 decreased by
13.7 percent
• Crashes with driver BAC levels at or above 0.15 also declined by 9.1 percent
Total incidents of drivers who tested positive for alcohol fell by 14.6 percent, whether or not
they were involved in a crash. While drivers were arrested for BAC levels between 0.05 and
4
National Highway Traffic Safety Administration (February 2022) “Evaluation of Utah’s .05 BAC Per Se Law.” DOT
HS 813 234
PER SE ALCOHOL 0.05 BAC
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0.079 due to the law change, the overall rates of arrest for DUI saw only a small increase over
previous levels. Clearly, the enforcement impacts of the change were not the primary driver of
the significant decreases in impaired driving and in all crash types. Education by all stakeholders
and public awareness are critical pieces and should therefore be the focus of a reduction in the
BAC per se limit.
These changes are significant in terms of lives saved and injuries prevented, and there are
substantial economic costs resulting from crashes that are avoided by preventing them. NHTSA
calculated comprehensive economic losses due to motor vehicle crashes in 2015. Fatal crashes
cost $9.15M per person killed in 2010 dollars. Costs associated with very serious injury crashes
ranged from $2.4M - $5.6M per person, depending upon the type, seriousness, and lasting
impacts of injuries sustained.
National Transportation Safety Board (NTSB) Recommendation
In their 2021-2022 “
Most Wanted List” the National Transportation Safety Board again stated
that all states should lower per se BAC levels to .05 percent or lower. According to the NTSB:
• 10,142 deaths occurred in crashes involving drivers with BACs of 0.08 or higher in 2019,
which was 28 percent of all traffic fatalities in the US that year.
• BAC levels as low as 0.01 have been associated with driving-related performance
impairment, and BAC levels as low as 0.05 have been associated with significantly
increased risk of fatal crashes.
• BAC levels higher than 0.05 are viewed by respected traffic safety and public health
organizations around the world as posing unacceptable risk for driving, and more than
100 countries have already established per se BAC limits at or below 0.05.
The World Health Organization (WHO) maintains a database of countries’ BAC limits. The list of
more than 100 countries with limits of 0.05 or lower includes Germany, India, Japan, Thailand,
Turkey, Columbia, Russia, South Africa, and the Philippines. In many of those countries, people
drink more per capita than in the U.S., but they are less likely to die in drunk driving crashes.
A recent review of fatal crashes in 29 high-income countries found that fatal crash rate per
100,000 in the U.S. was more than 30 percent higher than the next highest country (Poland).
The U.S. rates were more than double the international average and median among the 29
countries. The U.S. was one of only three countries with a per se BAC limit above 0.05.
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5
Center for Disease Control and Prevention, “Motor Vehicle Crash Deaths—United States and 28 Other High-
income Countries, 2015 and 2019,” Morbidity and Mortality Weekly, V. 71 No. 26, July 2022.
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Lower BAC, Fewer Fatal Crashes
Washington last reduced the per se BAC limit during a national push to make this change. As
states lowered their BAC to 0.08, many studies showed reductions of alcohol-involved fatal
crashes, both involving drivers with high and low BAC levels. These reductions ranged from 5
percent to 16 percent.
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A paper by James Fell and Robert Voas, “
The Effectiveness of a .0.05
Blood Alcohol Concentration (BAC) Limit for Driving in the United States,” pointed out the
following:
• The risk of a single-vehicle fatal crash increases substantially for drivers with a BAC of
.05-.079. It is at least 7 times greater than for a driver with a 0.00 BAC.
• All drivers are impaired at a 0.05 BAC, even heavy drinkers.
• Lowering the BAC limit to 0.05 is a proven effective countermeasure that has reduced
alcohol-related fatalities in other countries. For example, Australia who experienced an
18 percent reduction in fatal crashes and a 14 percent reduction in serious crashes
associated with lowering the BAC limit to 0.05.
The Costs of Fatal Crashes and Benefits of Preventing Them
In addition to the tragic and sudden loss of life, the CDC estimated the total cost of traffic crash
deaths in Washington in 2018 to be $930 million. Impaired driving is the number one
contributing factor to fatal crashes. Impairment also leads to increases in other risk factors,
such as speeding, lane and road departure, and the failure of impaired individuals to use seat
belts. Reducing impaired driving will save lives and save costs accrued to victims, their families,
insurance companies, law enforcement, courts, and all road users.
The NHTSA evaluation of the Utah law also evaluated the impact upon tax revenues, tourism,
and alcohol sales. They found that the predictions made by opponents that the law would
discourage tourism and alcohol sales did not materialize. Instead, NHTSA found that tourism
and beverage sales, and the resulting tax revenues, remained strong after the law change.
Reducing the per se BAC limit does not require people to purchase or consume less alcohol.
Rather, it merely requires them to avoid driving when they consume enough to be impairing.
6
International Journal of Environmental Research and Public Health, Published Sept. 27, 2013, “Effectiveness of
Drinking and Driving Policies for Different Alcohol-Related Fatalities.”