Modeling a national Graduated-BAC per se policy for 21-24 y/o drivers to reduce alcohol impaired driving injury and fatal crashes - PROJECT SUMMARY The national comprehensive societal cost from alcohol-impaired crashes is estimated at over $348 billion, with $296 billion attributable to ≥ .08 BAC cashes. In the last 10 years, the national alcohol impaired driving crash fatality rate has increased by 23%. Young drivers are the most vulnerable group and at highest risk of being seriously injured and/or killed in an alcohol impaired driving crash. Much of this vulnerability exists in the context of young drivers navigating life at a time when individual freedom and mobility via driving is high as is exposure and ease of access to alcohol and drugs. Prior to turning age 21, the Minimum Legal Drinking Age and Zero- Tolerance laws (making it unlawful for those <21y/o who drive to have a BAC ≥.02) are in effect for youth and young drivers with the intent of reducing harm and death due to negative consequences of alcohol use. However, when a young driver who drinks turns 21y/o, they are no longer subject to key effective alcohol prevention/public safety policies. Instead, when getting behind the wheel, they are subject to a BAC per se policy with a threshold of ≥.08 g/dl. Unfortunately, this is a higher BAC limit with a well-established greater risk of serious injury and fatal crash (i.e., BAC per se of ≥.02 before age 21 vs. a BAC per se of ≥ .08 upon turning age 21y/o). Given the current state of an increasing national alcohol crash fatality rate and high vulnerability of young adult drivers, there is a critical need and salient opportunity to innovate policy focused in the young-impaired driver domain. An early reduced risk exposure approach at the time young drivers turn 21y/o and can legally drink could yield measurable harm and fatality reduction effects. Except for the state of Utah, where the BAC per se policy is ≥.05, all US states are at a BAC per se of ≥.08. International studies prove reductions in BAC limits to .05 significantly reduce alcohol-impaired traffic injuries and deaths. Using epidemiologic and system dynamics methods, this study will provide a novel robust examination and modeling of a conceptual national age-based Graduated-BAC per se policy (Grad-BAC) so that at the moment a young driver turns 21y/o through age 24y/o, the BAC per se would be ≥.05. Thereafter, at age 25y/o, the BAC per se would be ≥.08 (except for Utah that is already at a BAC per se of ≥.05). This study will first examine longitudinal pre/post-age 21y/o driving after drinking behavior as well as state-/national-level crash fatalities specifically among drivers 21-24y/o by BAC levels. Further, changes in fatal crash rates among drivers 21-24y/o pre- vs. post-BAC per se policy of ≥.05 in Utah and in neighboring states will be evaluated. Next, national public survey and focus groups of state policy leaders will be conducted to assess support for or against the Grad-BAC per se policy vs. a national BAC per se of ≥.05 for all drivers ≥21y/o. Finally, the construction of a robust and comprehensive simulation system dynamics model will facilitate the examination of potential effects of the Grad-BAC policy among 21-24y/o that drive after drinking. This study will effectively leverage historical and recent landmark findings in impaired driving research and policy. Study findings will prove to be highly novel and pivotal in informing new policy and prevention efforts.
