Testimony before the Committee on Judiciary Hawai'i State Legislature on Senate Bill 160 Operating a Vehicle while Impaired/ .05 Blood Alcohol Concentration

​​​​Good afternoon, Chair Rhoads, Vice Chair Gabbard and Members of the Committee. Thank you for the opportunity for the National Transportation Safety Board (NTSB) to testify before you today.

The NTSB is an independent federal agency charged by Congress with investigating aviation, marine, and rail accidents, commercial space launch and re-entry mishaps, highway crashes, and hazardous materials releases, in pipelines and elsewhere in transportation.

We determine their probable causes and issue safety recommendations to prevent them from happening again. We also conduct safety research.

The NTSB has no power to regulate or legislate, and we rely on the persuasive power of our comprehensive investigations and research to encourage the recipients of our recommendations to act to improve safety. We appreciate the opportunity to testify on our recommendation to Hawaiʻi to lower its per se impairment threshold from .08 grams per deciliter blood alcohol concentration (BAC) to .05 grams per deciliter BAC.[1]

We have recommended that Hawaiʻi, and all states, the District of Columbia, and the Commonwealth of Puerto Rico, reduce the alcohol impairment threshold to .05 or lower.[2] We view the opportunity to testify today as an opportunity to support this committee’s important work to save lives—the predictable outcome of lowering the threshold to .05.

Simply put, .05 saves lives. The remainder of this testimony supports this conclusion.

Too many people are dying on our roads because of alcohol impairment. These deaths are 100 percent preventable. Fewer people will die with a change of the per se limit from .08 to .05. This change has been made elsewhere without adverse economic consequences.

The Persistent Problem: Impaired-Driving Crashes Still Kill Thousands

While the number of lives lost annually in alcohol-impairment crashes declined by more than half from 21,113 in 1982 to 10,136 in 2010,[3,4] there has not been improvement since that time. In fact, in 2020, there were 11,654 alcohol-impaired driving fatalities, the highest number ​​2008. [5,6] Impaired driving crashes hit people in the pocketbook too. The National Highway Traffic Safety Administration (NHTSA) last estimated the economic cost of all alcohol-involved crashes in the U.S. at $68.9 billion for the year 2019.[7] So while the ongoing tragedy of impaired driving can strike anybody, its economic burden does strike everybody.

Due to this lack of continued progress in reducing the impact of impaired driving, in 2012, an NTSB forum called “Reaching Zero” kicked off a year-long effort to assess impaired-driving countermeasures. The effort culminated with a 2013 report, “Reaching Zero: Actions to Eliminate Alcohol-Impaired Driving,” [8] which identified the most effective, scientifically based actions that could save lives presently lost to alcohol-impaired driving. One of these actions was to lower the per se impaired driving limit from .08 BAC to .05 BAC or lower for all drivers.[9]

The (Present) .08 BAC Limit

From 2006 to 2017[10], all states had a per se BAC threshold of .08 for noncommercial drivers age 21 and over. But .08 BAC is not when impairment begins. A 2015 NHTSA study showed that crash risk at .05 was double that of a sober driver. But at .08, crash risk roughly doubled again to about four times the sober driver’s risk.[11]

What Happens When You Lower the Per Se BAC Limit to .05

The advantage of a per se BAC limit of .05 or lower is that it does not only deter driving between .05 BAC and .079 BAC (that is, the specific concentrations newly above the threshold) but lowering the BAC limit has also been shown to reduce impaired driving fatalities even at higher BAC levels.[12] 

​To reduce alcohol-related crashes, many countries have established a BAC limit of .05, and the benefits of the lowering BAC limits have been documented.[13] Currently, more than 100 countries have BAC limits set at .05 or lower.[14] A 2017 study estimated that this standard could result in an estimated 11 percent decline in fatal alcohol-related crashes and save at least 1,700 lives annually in the United States.[15]

The Utah Experience

On March 23, 2017, the Governor of Utah signed a law to lower the state’s BAC limit for noncommercial drivers from .08 to .05, effective December 30, 2018. Initial data are promising. In February 2022, NHTSA published a report entitled “Evaluation of Utah’s .05 BAC Per Se Law,” which compared the state’s crash data before and after the law went into effect. [16]

The report found there was a reduction in crashes and fatalities, as compared to the rest of the country. When vehicle miles traveled (VMT) is considered, the fatal crash rate reduction from 2016 to 2019 in Utah was 19.8 percent, and the fatality rate reduction was 18.3 percent. In comparison, the rest of the United States showed a 5.6 percent fatal crash rate reduction and 5.9 percent fatality rate reduction during the same time. In addition, the neighboring States of Arizona, Colorado, and Nevada did not show the same levels of improvement in fatal crash and fatality rates as Utah.

Further, the study found that there was no impact on alcohol sales, tax revenues, or tourism, nor were there substantially increased arrests.

Support for .05

National and international traffic safety and public health organizations, including the American Medical Association; the World Health Organization; the World Medical Association; the Association for the Advancement of Automotive Medicine; the National Academies of Science, Engineering, and Medicine; the American Public Health Association, Advocates for Highway and Auto Safety; and Mothers Against Drunk Driving have advocated setting BAC limits at .05 or lower.


Progress toward eliminating alcohol-impaired driving fatalities has unnecessarily stagnated. More can and should be done to prevent these tragedies.

​​The evidence is clear: per se BAC limits of .05 or lower can save lives and have saved lives. Utah saw an 18.3 percent reduction in its fatality rate between 2016 and 2019 following the passage of .05 legislation.

The NTSB believes that the only acceptable number of deaths on our roads is zero, and it has been our charge since our founding to determine how to eliminate transportation fatalities. Deaths due to impaired driving are 100 percent preventable, and Hawai’i can be a leader in implementing policies that will save lives and prevent impaired driving.

[1] For the remainder of this testimony, we use the common shorthand of .08 and .05, omitting repeated references to units of measure for BAC and breath alcohol concentration (BrAC). Blood Alcohol Concentration (BAC) is commonly rendered without units, but it stands for the grams of alcohol per tenth of a liter, or deciliter, of blood. Breath Alcohol Concentration (BrAC) uses grams of alcohol per 210 liters of breath (alcohol is 2,100 times more concentrated in blood than in breath). As a result, .05 g/dL BAC, for example, is considered the equivalent of .05 g/210 liters BrAC. ​
[3] National Transportation Safety Board. 2013. Reaching Zero: Actions to Eliminate Alcohol-Impaired Driving. Safety Report NTSB/SR-13/01. Washington, DC: NTSB. 
[4] National Center for Statistics and Analysis. (2021, July). Alcohol Impaired Driving. (Traffic Safety Facts. Report No. DOT HS 813 120). Washington, DC: National Highway Traffic Safety Administration, Table 4, accessed 2/17/22​​
​[5] The National Highway Traffic Safety Administration (NHTSA) reports drivers as alcohol-impaired at .08 BAC or greater. However, in 2019, an additional 1,775 people were killed in alcohol-related crashes where a driver had a BAC of .01 to .07 g/dL. https://www.nhtsa.gov/risky-driving/drunk-driving, accessed 1/13/22
[6] Stewart, T. (2022, March). Overview of motor vehicle crashes in 2020 (Report No. DOT HS 813 266). National Highway Traffic Safety Administration.
[7] Blincoe, L., Miller, T., Wang, J.-S., Swedler, D., Coughlin, T., Lawrence, B., Guo, F., Klauer, S., & Dingus, T. (2022, December). The economic and societal impact of motor vehicle crashes, 2019 (Report No. DOT HS 813 403). Washington, DC: National Highway Traffic Safety Administration. Available at https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813403
[8] National Transportation Safety Board. 2013. Reaching Zero: Actions to Eliminate Alcohol-Impaired Driving. Safety Report NTSB/SR-13/01. Washington, DC: NTSB. 
[10] In 2017, Utah lowered its per se threshold to .05 BAC, effective December 30, 2018 (see “The Utah Experience”).
[11] National Center for Statistics and Analysis. (2015, February). Drug and Alcohol Crash Risk. (Traffic Safety Facts Research Note. Report No. DOT HS 812 117). Washington, DC: National Highway Traffic Safety Administration, Table 8.
[12] National Academies of Sciences, Engineering, and Medicine. 2018. Getting to Zero Alcohol-Impaired Driving Fatalities: A Comprehensive Approach to a Persistent Problem. Washington, DC: The National Academies Press. https://doi.org/10.17226/24951.
​​​​[13] Fell, J. C. & M. Scherer. 2017. “Estimation of the potential effectiveness of lowering the blood alcohol concentration (BAC) limit for driving from 0.08 to 0.05 grams per deciliter in the United States.” Alcoholism: Clinical and Experimental Research. 41(12) 2128-2139.
[14] https://apps.who.int/gho/data/view.main.54600
[15] Fell, J. C., & Scherer, M. (2017). Estimation of the Potential Effectiveness of Lowering the Blood Alcohol Concentration (BAC) Limit for Driving from 0.08 to 0.05 Grams per Deciliter in the United States. Alcoholism, clinical and experimental research, 41(12), 2128–2139. https://doi.org/10.1111/acer.13501.
[16] National Center for Statistics and Analysis. (2022, February). Evaluation of Utah’s .05 BAC Per Se Law. (Traffic Tech Technology Transfer Series. Report No. DOT HS 813 234). Washington, DC: National Highway Traffic Safety Administration.