Blood Alcohol Concentration (BAC) Limits: Youth (Underage Operators of Noncommercial Motor Vehicles)

(Period Covered: 1/1/1998 through 1/1/2012)

This policy topic covers laws addressing blood alcohol concentration limits applicable to drivers of noncommercial automobiles, trucks, and motorcycles who have not reached the legal drinking age of 21 years.  

Blood alcohol concentration (BAC) is a measure of the amount of alcohol in a person's bloodstream. BAC is commonly expressed in percentage terms. For instance, having a BAC of 0.08 percent means that a person has eight parts alcohol per 10,000 parts blood in the body. State laws generally specify BAC levels in terms of grams of alcohol per 100 milliliters of blood (often abbreviated as grams per deciliter, or g/dL). BAC levels can be detected by breath, blood, or urine tests. The laws of each jurisdiction specify the preferred or required types of tests used for measurement.

BAC statutes establish criteria for determining when an operator of a vehicle is violating the law. This section provides information on State and Federal BAC laws that apply to drivers of noncommercial automobiles, trucks, and motorcycles who have not reached the legal drinking age (21 years). Laws establishing very low legal BAC limits of .02 g/dL or less for drivers under the legal drinking age of 21 have been widely referred to as "zero-tolerance laws".  Partly as a result of financial incentives established by the Federal government, all States and the District of Columbia have enacted low BAC limits for young drivers.

All jurisdictions have enacted per se BAC laws for youth operating noncommercial motor vehicles.  A per se BAC statute establishes a BAC limit for a violation. If the operator has a BAC level at or above the per se limit, a violation has occurred without regard to other evidence of intoxication or sobriety. In other words, exceeding the BAC limit established in a per se statute is itself a violation.  By limiting the use of evidence by defendants, per se laws make conviction more likely. [1].  

In the past, some States without a per se law established other standards for using BAC levels as evidence of being under the influence of alcohol. In these jurisdictions, the weight given to the BAC evidence varied. Some laws provided that a BAC at or above a particular level created a presumption of being under the influence of alcohol. Other laws provided that such evidence was prima facie evidence of being under the influence, or was admissible in making this determination. These evidentiary standards were even weaker than a presumption. Defendants in jurisdictions without a per se standard could provide evidence that, in spite of the BAC level, they were not under the influence and therefore not in violation. This differentiates other statutes from per se statutes, which provide that exceeding the BAC limit is itself a violation and only the validity of the BAC measurement is at issue.

For historical data, APIS distinguishes between per se and non-per se jurisdictions but does not distinguish the evidentiary weight of BAC evidence in jurisdictions without a per se standard.

[1] Cowan, J. and Joffie, S. "Proof and disproof of alcohol-induced driving impairment through blood alcohol testing," 4 Am. Jur. POF 3d 229 (July 2002).

Explanatory Notes and Limitations Specifically Applicable to Blood Alcohol Concentration Limits: Youth (Underage Operators of Noncommercial Motor Vehicles) 

1. This review examines only the specific BAC laws for underage drivers in each State and the District of Columbia and the specific Federal legislation cited. 

2. This review does not address the following issues related to BAC limit laws:

• Penalties for violations of BAC laws.
• State and Federal laws related to enforcement of BAC laws.
• Provisions covering enhanced sanctions for violators whose BAC exceeds a specified level that is higher than the legal limit (e.g., BAC > 0.20 g/dL).
• Provisions related to repeat offenders.
• Provisions that create a rebuttable presumption of impairment or other evidentiary standard at lower levels of BAC than the per se limits.
• BAC limits applied to operators of commercial motor vehicles.
• Applicability of BAC limits for youth operators of motor vehicles to other forms of transportation such as snowmobiles and watercraft.
• Federal law pertaining exclusively to the military.
• Laws that may pertain to BAC limits for those who operate nonmotorized bicycles.
• Separate laws for Indian Reservations. Approximately 200 tribes across the Nation have jurisdiction and responsibility for laws affecting their reservations. Many have passed their own BAC laws.

Explanatory Notes and Limitations Applicable to All APIS Policy Topics

1. State law may permit local jurisdictions to impose requirements in addition to those mandated by State law. Alternatively, State law may prohibit local legislation on this topic, thereby preempting local powers. APIS does not document policies established by local governments.

2. In addition to statutes and regulations, judicial decisions (case law) also may affect alcohol-related policies. APIS does not review case law except to determine whether judicial decisions have invalidated statutes or regulations that would otherwise affect the data presented in the comparison tables.

3. APIS reviews published administrative regulations. However, administrative decisions or directives that are not included in a State's published regulatory codes may have an impact on implementation. This possibility has not been addressed by the APIS research.

4. Statutes and regulations cited in tables on this policy topic may have been amended or repealed after the specific date or time period specified by the site user's search criteria.

5. A comprehensive understanding of the data presented in the comparison tables for this policy topic requires examination of the applicable Row Notes and Jurisdiction Notes, which can be accessed from the body of the table via links in the Jurisdiction column.

 

(Policies in effect on: 1/1/2012)

In 1995, Congress enacted legislation that required the withholding of a portion of a State's Federal highway funds if the State did not adopt a 0.02 or lower BAC limit for underage operators of motor vehicles [23 U.S.C. § 161]. In 1988, Congress offered supplemental grants to States that enacted BAC limits of 0.02 or less for drivers under the age of 21 [23 U.S.C. § 410].

FEDERAL CITATIONS AND RELEVANT TEXT EXCERPTS

1. Carpenter, C. How do zero tolerance drunk driving laws work? Journal of Health Economics 23(1):61-83, 2004.
    
2. Fell, J.C., Fisher, D.A., Voas, R.B., Blackman, K., and Tippetts, A.S. The impact of underage drinking laws on alcohol-related fatal crashes of young drivers. Alcoholism: Clinical and Experimental Research 33(7):1208-19, 2009.
    
3. Fell, J.C., Fisher, D.A., Voas, R.B., Blackman, K., and Tippetts, A.S. The relationship of underage drinking laws to reductions in drinking drivers in fatal crashes in the United States. Accident Analysis and Prevention 40(4):1430-1440, 2008.
    
4. Lovenheim, M.F., and Slemrod, J. The fatal toll of driving to drink: The effect of minimum legal drinking age evasion on traffic fatalities. Journal of Health Economics 29(1):62-77, 2010.
    
5. Maldonado-Molina, M.M., Reingle, J.M., Delcher, C., and Branchini, J. The role of parental alcohol consumption on driving under the influence of alcohol: Results from a longitudinal, nationally representative sample. Accident Analysis and Prevention 43(6): 2182-2187, 2011.
    
6. McCartt, A.T., Hellinga, L.A., and Kirley, B.B. The effects of minimum legal drinking age 21 laws on alcohol-related driving in the United States. Journal of Safety Research 41(2):173-81, 2010.
    
7. National Institute on Alcohol Abuse and Alcoholism. Alcohol and Transportation Safety. Alcohol Alert No. 52. Rockville, MD: NIAAA, 2001.
    
8. Norberg, K.E., Bierut, L.J., and Richard, A.G. Long-term effects of minimum drinking age laws on past-year alcohol and drug use disorders. Alcoholism: Clinical and Experimental Research 33(12), 2009.
    
9. Peck, R.C., Gebers, M.A., Voas, R.B., and Romano, E. The relationship between blood alcohol concentration (BAC), age, and crash risk. Journal of Safety Research 39(3):311-9, 2008.
    
10. Roudsari, B., and Ramisetty-Mikler, S. Exceptions to the ‘national minimum drinking age act’ and underage drunk driver death in the United States: A state-level comparison. Annals of Epidemiology 18(9):714-714, 2008.
     
11. Voas, R.B., Tippetts, A.S., and Fell, J. Assessing the effectiveness of minimum legal drinking age and zero tolerance laws in the United States. Accident Analysis and Prevention 35(4):579-87, 2003.
     
12. Zakrajsek, J.S., and Shope, J.T. Longitudinal examination of underage drinking and subsequent drinking and risky driving. Journal of Safety Research 37(5):443-451, 2006.