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Effectiveness: 3 Star Cost: $
Use: Medium
Time: Short

Almost all States increase the penalties for the standard impaired-driving (DWI) offense for repeat offenders. Some States also have enhanced sanctions for drivers with high BACs, typically above .15 g/dL. In 2021 two-thirds (67%) of alcohol-impaired-driving fatalities were in crashes that each involved at least one driver with a BAC of .15 g/dL or higher (NCSA, 2023a).

High-BAC sanctions are based on the observation that many high-BAC drivers are habitual impaired-driving offenders, even though they may not have records of previous arrests and convictions. Moreover, drivers with high BACs put themselves and other road users at even greater risk; over half (55%) of the drivers with positive BACs involved in fatal crashes in 2021 had BACs of .15 g/dL or greater (NCSA, 2023a). Enhanced sanctions for high-BAC drivers vary by State and may include mandatory assessment and treatment for alcohol misuse problems, close monitoring or home confinement, installation of an ignition interlock, and vehicle or license plate sanctions. NHTSA recommends sanctions for first-time offenders with high BACs be comparable to those for repeat offenders (NHTSA, 2008c).


As of March 2023 all States except Alaska, Arkansas, Connecticut, Hawaii, Mississippi, and Vermont had increased penalties for drivers with high BACs (GHSA, 2023). The definition of high BAC ranges from .10 to .20 g/dL, but the most common is .15 g/dL (23 States). Additionally, some States have several levels of high BACs, with sanctions escalating with increasing BACs. See the National Conference of State Legislatures (2016a) for more information about State penalties for high BACs.


In the only evaluation of high-BAC sanctions to date, McCartt and Northrup (2003, 2004) examined Minnesota’s high-BAC law that included administrative license impoundment and more severe post-conviction penalties for drivers with BACs of .20 g/dL or higher. The one-year recidivism rate was significantly lower for the high-BAC offenders compared to those with BACs from .17 and .19 g/dL (who also had relatively high BACs but were not subject to the enhanced sanctions). This suggests the sanctions were successful at preventing future impaired driving. However, the researchers did not examine the effect of high-BAC laws on alcohol-impaired-driving crashes or fatalities.


In the short run, high-BAC sanctions may produce increased costs for interlocks, treatment, and other sanctions. Over a longer period, if high-BAC sanctions reduce recidivism and deter alcohol-impaired driving, then costs will decrease.

Time to Implement:

High-BAC sanctions can be implemented as soon as appropriate legislation is enacted.

Other considerations:

  • Test refusal: High-BAC sanctions may encourage some drivers to refuse an officer’s request for a BAC test unless the penalties for test refusal are at least as severe as the high-BAC penalties. See the next countermeasure on BAC test refusal penalties for more information.
  • Child endangerment laws: Like high-BAC laws, child endangerment laws recognize there are certain instances where impaired drivers pose extreme risk to others. In 2019 there were 204 children 14 or younger (19% of all child fatalities) who were killed in alcohol-impaired-driving crashes (NCSA, 2023a). Of those, 109 were occupants of vehicles with drivers who had BACs of .08 g/dL or higher. Child endangerment laws create a separate offense or enhance DWI penalties for impaired drivers who carry children. As of 2018 there were 46 States and the District of Columbia that had separate or higher penalties for impaired drivers who have children in their vehicles (Mothers Against Drunk Driving, 2018). Unfortunately, research suggests child endangerment laws do not reduce fatalities among young passengers (Kelley-Baker & Romano, 2016). Reasons for the lack of effectiveness include inadequate publicity, issues with enforcement, and inconsistently applied sanctions by the court system.