"Despite years of progress, alcohol-impaired driving remains the deadliest and costliest danger on U.S. roads today. The causes of alcohol-impaired driving are complex and multifaceted, but these deaths are entirely preventable." - National Academies of Sciences, Engineering, Medicine
In order to significantly lower the amount of DUI-related deaths, the National Academies of Sciences, Engineering, and Medicine recommend lowering the legal B.A.C. (blood alcohol content) while driving to .05. Their 500 page report, which you can see here, outlines a comprehensive approach to stopping alcohol-impaired driving fatalities.
Liam's Life Foundation is committed to campaigning for the lowering of the legal B.A.C. from .08 to .05, beginning in our home state of California & taking the fight to the rest of the country.
- At .05 BAC, tracking, steering, coordination and emergency response are all affected. (NHTSA)
- .05 is the international standard — over 100 countries have BAC limits of .05 or lower.
- In Europe, only Malta and parts of the United Kingdom still have a .08 BAC limit. All other countries are at or below .05, with some as low as .00. (ETSC)
- In Canada, only Quebec allows driving with a BAC above .05. (Blais et al.); Saskatchewan lowered to .04 on January 1, 2017 (CTV News)
- Alcohol-related deaths fell when states went from .10 to .08 but are rising: Alcohol-impaired driving fatalities increased 3.2% from 2014 to 2015. (GHSA)
- In 2013, the National Transportation Safety Board recommended that all states lower their BAC limit to .05 or lower. (NTSB) (Video annoucement, Deborah Hersman)
- Utah is not the only state considering making this change. (Washington, Hawaii)
- Utah and Oregon were the first states to lower from .10 to .08 in 1983. All 50 states and the District of Columbia lowered the BAC limit to .08 by 2005.
- HB 155 includes a delayed implementation date of December 30, 2018 to allow everyone involved time to adjust.
- Utah law already states that .05 is dangerous. Liquor licensees that provide breathalyzers must post a notice that states: "The National Transportation Safety Board has found that crash risk is consistently and significantly elevated by the time an individual reaches a blood alcohol content of 0.05." (UCA 32B-5-311)
What do Studies Show?
- Lowering to a .05 BAC limit law will save lives (Fell and Voas 2006)
- Impairment begins with the very first drink (NIH/NIAA Alcohol Alert 2001, Phillips and Brewer 2011)
- By 0.04 BAC all measures of impairment are statistically significant; Impairment is solely determined by BAC content (Driver Impairment and Characteristics at Various BACs, Moskowitz, et al. August 2000)
- People who drive will be less likely to drive at all levels of drinking – .05 BAC has a broad deterrent effect and changes behavior at all BAC levels (Wagenaar et al. 2007)
- A .05 BAC limit prevents impaired driving (Mann et al. 2001)
- Impaired drivers engage in other risky behaviors (Thygerson et al. 2011)
- The move from .10 to .08 reduced alcohol-related fatalities by 10.4%, saving a total of 23,686 lives in the U.S. Moving from .08 to .05 would add another 11.1% decline, saving 1,790 lives annually (NORC 2017, Community Preventive Services Task Force, 2000)
- Most people would not drive after consuming 2-3 drinks in an hour and believe that the law should reflect that level of drinking (which equates to .05 or lower) (Moulton et al. NHTSA 2008; AAA Foundation 2005)
- The relative risk of being killed in a single-vehicle crash with BAC between .05 & .08 is 7 to 21 times that of a person with .00 BAC. (NIH/NIAA Alcohol Alert 2001, Fell and Voas 2014)
- Crash risk grows exponentially with increasing BAC, starting with very low levels. (Compton and Berning, NHTSA, 2015)
- Current law enforcement tools will work for .05 BAC. (McKnight et al. 2003)
The effectiveness of a 0.05 blood alcohol concentration (BAC) limit for driving in the United States
The National Transportation Safety Board recently recommended that states establish a per se blood alcohol concentration (BAC) limit of 0.05 or lower for all drivers who are not already required to adhere to lower BAC limits in a national effort to reduce alcohol-impaired driving. There is strong evidence for adopting this recommendation. A comprehensive review of the literature on BAC limits was conducted. The research indicates that virtually all drivers are impaired regarding at least some driving performance measures at a 0.05 BAC. The risk of being involved in a crash increases significantly at 0.05 BAC and above. The relative risk of being killed in a single-vehicle crash with BACs of 0.05–0.079 is 7–21 times higher than for drivers at 0.00 BAC. Lowering the BAC limit from 0.08 to 0.05 has been a proven effective countermeasure in numerous countries around the world. Most Americans do not believe a person should drive after having two or three drinks in 2 hours. It takes at least four drinks for the average 170-pound male to exceed 0.05 BAC in 2 hours (three drinks for the 137-pound female). Most industrialized nations have established a 0.05 BAC limit or lower for driving. Progress in reducing the proportion of drivers in fatal crashes with illegal BACs has stalled over the past 15 years. Lowering the BAC limit for driving from the current 0.08 to 0.05 has substantial potential to reduce the number of people who drink and drive in the United States and get involved in fatal crashes.
On 14 May 2013, the National Transportation Safety Board (NTSB), an independent federal agency dedicated to promoting transportation safety, issued a report recommending, among other measures, that states should lower the illegal blood alcohol concentration (BAC) limit for driving from 0.08 to 0.05 . The NTSB provided a sound rationale and concluded that lowering the BAC limit to 0.05 or lower has a strong evidence-based foundation. Most industrialized nations have already enacted a 0.05 illegal BAC limit.
The American Beverage Institute, funded by the alcohol and hospitality industries, countered the recommendation stating that it was ‘ludicrous’ and ‘criminalizing perfectly responsible behavior’ . There was also a lack of enthusiastic support from some organizations, such as Mothers Against Drunk Driving, who questioned of the potential benefit of a 0.05 BAC law. This raises the issue for debate as to whether enactment of a law reducing the illegal BAC limit for driving to 0.05 will be an effective strategy in the United States. In our experience with lower BAC limits in the United States, the following issues have typically been raised by opponents.
Issue: there is little increase in crash risk at 0.05 BAC
A review of the literature by researchers from the Pacific Institute for Research and Evaluation examined the effects of various BACs on driving and crashes . The review revealed important reasons why a 0.05 illegal BAC limit is a sound strategy. The risk of being involved in a crash of any severity increases at each positive BAC level, but the risk rises rapidly and is statistically significant after a driver reaches or exceeds 0.05 BAC compared to drivers with no alcohol in their blood systems . Recent studies indicate that the relative risk of being killed in a single-vehicle crash for drivers with BACs of 0.05–0.079 is at least seven times that of drivers at 0.00 BAC (no alcohol). These risks are significant [5,6].
Issue: many people are not impaired at 0.05 BAC
Laboratory evidence shows that most adults are significantly impaired at 0.05 BAC [7–9]. For example, Moskowitz & Fiorentino  reviewed 112 scientific papers regarding the effects of alcohol on driving-related skills published between 1981 and 1997. They concluded that, by the time subjects reach 0.05 BAC, the majority of experimental studies examined reported significant impairment. After testing 168 drivers in another study, Moskowitz et al.  concluded that most of the driving population is impaired in at least some important measures at BACs as low as 0.02 BAC.
Issue: heavy drinkers are not impaired at 0.05 BAC
Drivers with 0.05–0.07 BACs are also much more likely to be involved in a fatal crash than drivers who have not been drinking . The driving performance of virtually all drivers is impaired at 0.05 BAC. Laboratory and test track research shows that most drivers, even experienced drinkers who typically reach BACs of 0.15 or greater, are impaired at 0.05 BAC regarding critical driving tasks . There are significant performance decrements in areas such as braking, steering, lane-changing, judgement and divided attention at a 0.05 of BAC. Some studies report that inadequate, reduced or compromised performance decrements in some of these tasks are as high as 30–50% at 0.05 BAC compared to the same drivers at 0.00 BAC [7–10].
Issue: lowering the limit to 0.05 will have little effect on fatal crashes
Lowering the illegal BAC limit to 0.05 is a proven effective countermeasure that has reduced alcohol-related traffic fatalities in other countries, most notably Australia (see Table 1). Although studies in Europe and Australia each use a different methodology to evaluate these effects, the evidence is consistent and persuasive that fatal and injury crashes involving drinking drivers decrease at least 5–8% and up to 18% after a country lowers their illegal BAC limit from 0.08 to 0.05 illegal BAC (e.g. [11–17]). If all states were to adopt the 0.05 illegal BAC limit, and it was enforced, an estimated 500–800 lives could be saved each year in the United States [18,19]. When the BAC limit was lowered in states in the United States from 0.10 to 0.08, numerous studies showed that it reduced impaired-driving fatal crashes [18–22].
Issue: countries most like us, Britain and Canada, still have 0.08 BAC limits
Most other industrialized nations around the world have set illegal BAC limits at 0.05 BAC or lower. Most Canadian provinces have a 0.05 ‘warn range’ limit at which officers may suspend the driver’s license for 1–7 days. In a recent study, the 0.05 warn range in British Columbia in Canada (a 3-day administrative license suspension for driving with a BAC from 0.05 to 0.07) was associated with a 40% decrease in alcohol-related fatal crashes . In Britain, a national per se BAC limit of 0.08 was enacted in 1967, a full 16 years before any state in the United States adopted that limit. Many states in the United States that had BAC limits in 1967 set them at 0.15. Establishing the 0.08 per se BAC limit, coupled with a strong enforcement effort, produced a marked reduction in alcohol-related crashes in Britain .
All states in Australia now have a 0.05 illegal BAC limit. Austria, France, Germany, Italy and Spain have lowered their limit to a 0.05 illegal BAC; and Japan, Norway, Russia and Sweden have set their limit at 0.02 illegal BAC .
Issue: the US public will not support a 0.05 limit
A reasonable standard to set is 0.05 illegal BAC. A 0.05 illegal BAC is not typically reached with a couple of beers after work or with a glass of wine or two with dinner. It takes at least four drinks for an average 170-pound male to exceed 0.05 BAC in 2 hours on an empty stomach (three drinks for a 137-pound female). The illegal BAC level reached depends upon a person’s age, gender and weight, as well as the food in their stomach and their metabolism rate . No matter how many drinks it takes to reach 0.05 BAC, people at this level are too impaired to drive safely.
The public supports levels below 0.08 BAC. The National Highway Traffic Safety Administration (NHTSA) national opinion surveys show that most people would not drive after consuming two or three drinks in an hour and believe the limit should be no higher than the BAC level associated with that amount of drinking , which would be 0.05 BAC or lower for most drivers.
Issue: police will have difficulty enforcing the 0.05 BAC limit
Several studies, including a NHTSA-sponsored study in Illinois , have looked at the impact of lowering the BAC limit from 0.10 to 0.08 on enforcement efforts and the criminal justice system. These studies have not found any significant problems for the police or for the court systems in adjusting to a lower limit. The same should happen when the limit is lowered from 0.08 to 0.05 BAC. There will be a slight increase in driving while impaired (DWI) arrests, but not enough to overburden the criminal justice system. Lowering the per se limit to 0.05 does not place an unnecessary strain on police officers. They must still have probable cause to stop drivers and to determine if they are impaired. The horizontal gaze nystagmus (HGN) test of the three Standardized Field Sobriety Tests (SFSTs) is just as valid at 0.05 BAC as it is at 0.08 BAC and 0.10 BAC .
Issue: drivers under age 21 years, who are at highest risk for being involved in a crash, will not be affected by the 0.05 law because they are already under the 0.02 zero-tolerance law
Issue: the 0.05 law will not affect the high-BAC hard-core drinking drivers
Legislation lowering the BAC limit has been shown to significantly reduce drinking drivers in fatal crashes at all BAC levels (BACs > 0.01; 0.05; 0.08; 0.15) [12,18,19,21,22]. In one study, lowering the illegal BAC limit from 0.10 BAC to 0.08 BAC was associated with an 18% decrease in the proportion of fatal crashes with a fatally injured driver whose BAC was 0.15 or greater . As shown in Fig. 1, during the last 30 years impaired driving laws and enforcement in the United States have contributed to reductions of impaired drivers in fatal crashes (BACs ≥ 0.08). In addition, laws such as lowering BAC limits for driving have also resulted in reductions of drivers in fatal crashes with very high BACs (0.15 or greater) [18,19,22].
The proportion of drivers in fatal crashes with illegal BACs (≥0.08) has been reduced significantly from 35% in 1982 to 20% in 1999 (P < 0.05), a 43% decrease in that proportion. In addition, the proportion of drivers in fatal crashes with very high BACs (≥0.15) has also decreased significantly, from 23% in 1982 to 13% in 1999 (P < 0.05), also a 43% reduction in that proportion.
Issue: the US impaired-driving enforcement system is working well
Progress to reduce impaired driving has stalled over the past 15 years (see Fig. 1). Between 1982 and 1997, there was a 43% reduction in the proportion of drivers involved in fatal crashes with BACs ≥ 0.08 and with BACs ≥ 0.15. Since then, there has been no progress in those measures. Further progress is needed to reduce alcohol-impaired driving in the United States. It has been 30 years since the first two states adopted a 0.08 illegal BAC limit (Utah and Oregon in 1983) and 13 years since federal legislation provided a strong incentive to adopt a 0.08 illegal BAC limit . Lowering the illegal BAC limit from 0.08 to 0.05 has substantial potential to reduce alcohol-impaired driving and save lives.
Issue: few scientific and safety organizations are supporting a 0.05 BAC limit
The World Medical Association, the American Medical Association, the British Medical Association, the European Commission, the European Transport Safety Council, the World Health Organization, the Canadian Medical Association, the Centre for Addiction and Mental Health and the Association for the Advancement of Automotive Medicine all have policies supporting a 0.05 BAC or lower as the illegal limit per se for drivers aged 21 years and older. At least 91 countries around the world have adopted a 0.05 illegal BAC or lower limit for driving, while 54 countries use limits from 0.06 to 0.12 illegal BACs .
The driving performance of virtually all drivers is impaired at 0.05 BAC, and the risk of being involved in a crash increases significantly at 0.05 BAC. Lowering the illegal per se limit to 0.05 BAC is a proven effective countermeasure that has reduced alcohol-related traffic fatalities in other countries. A 0.05 BAC limit is a reasonable standard to set: it is not typically reached with a couple of beers after work or with a glass of wine or two with dinner. The American public supports levels below 0.08 BAC. Surveys show that most people would not drive after consuming two or three drinks in an hour, which would be 0.05 BAC or lower for most drivers. Most other industrialized nations around the world have set BAC limits at 0.05 BAC or lower. Further progress is needed in reducing alcohol-impaired driving in the United States. Legislation such as lowering the BAC limit for driving typically reduces drinking drivers in fatal crashes at all BAC levels (BACs > 0.01; 0.05; 0.08; 0.15).
The major criticisms of a 0.05 BAC limit have been addressed. It is our opinion that the evidence is quite clear—lowering the BAC limit to 0.05 has saved lives in other countries and can do so in the United States. It is time we learned some lessons from our European and global partners in achieving further declines in impaired-driving fatalities . Lowering the illegal BAC limit for driving can serve as the impetus in further reducing alcohol-impaired traffic fatalities in this country.
The authors would like to thank Andrew Murie, Chief Executive Officer of MADD Canada, for funding the original review we conducted and published in 2009 . The contents and opinions are solely those of the authors and do not necessarily represent the views of our various research sponsors.
Declaration of interests
The authors declare no conflicts of interest regarding the content in this paper. This paper is based in some respects on a publication by the authors in 2009 .