DWI
Publication Date: 12/07/2009
The Problem:
The operation of motor vehicles while intoxicated is a major public health problem. Each year in the United States roughly 13,400 people die and an additional 255,500 are injured in motor vehicle crashes involving an alcohol-impaired driver. These crashes account for 32 percent of all U.S. traffic-related deaths and cost roughly $51 billion a year. CDC: Impaired Driving Factsheet.
The Law:
Blood alcohol per se laws set a blood alcohol limit at which an individual is considered legally impaired (i.e., impairment is “per se” because actual inability to function need not be established). Currently, all states set their BAC limit at 0.08 percent; some previously set the BAC levels at 0.10 percent. For examples of BAC per se laws, see Cal. Veh. Code §23152 (California), Fla. Stat. §316.193 (Florida), K.S.A. §8-1567 (Kansas), M.R.S. §2411 (Maine), N.M. Stat. Ann. §66-8-102 (New Hampshire), N.M. Stat. Ann. §66-8-102 (New Mexico), N.C. Gen. Stat. §20-138.1 (North Carolina), O.R.S. 813.010 (Oregon), Utah Code §41-6a-502 (Utah), 23 V.S.A. §1201 (Vermont), and Va. Code Ann. §18.2-266 (Virginia).
The Evidence:
In a Community Guide systematic review, Shults et al. reviewed eight studies that examined the impact of lowering the BAC limit to 0.08 percent on the rate of alcohol-related motor-vehicle deaths. Shults, et al. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. Am J Prev Med. 2001;21(4S):66-88.According to the reviewers, the underlying studies reveal a considerable association between the adoption of 0.08 percent BAC laws and a decline in alcohol-related motor-vehicle deaths; the median reduction in motor vehicle fatalities after the laws were adopted was 7 percent. Shults et al view these studies as strong evidence of the effectiveness of 0.08 BAC laws as a public health intervention. However, they caution that most of the BAC laws analyzed were enacted along with, or were supplemented by, other preventive drunk-driving laws, such as Administrative License Revocation (ALR) laws, making it difficult to isolate the exact magnitude of the impact of BAC laws.
The Bottom Line:
In the judgment of a Community Guide expert panel, there is strong evidence that laws adopting decreased BAC levels effectively reduce alcohol-related motor-vehicle deaths.
Additional Information:
The Community Guide provides online access to a table summarizing the results of each study it reviewed.
Additional Resources: The Community Guide
Publication Date: 12/07/2009
The Problem:
The operation of motor vehicles while intoxicated is a major public health problem. Each year in the United States roughly 13,400 people die and an additional 255,500 are injured in motor vehicle crashes involving an alcohol-impaired driver. In 2006, these crashes accounted for almost a third of all U.S. traffic-related deaths. CDC: Impaired Driving Factsheet.
The Law:
In an effort to reduce drunk-driving recidivism, municipalities and states have experimented with ignition interlock programs. Ignition interlock devices disable a car’s ignition until the driver provides a breath sample that confirms that the driver’s blood alcohol content (BAC) is under the requisite limit. Participation in ignition interlock programs is sometimes required as a condition of sentences for violating drunk- driving laws. Initially, participation in the US was generally on a voluntary basis (e.g., violators could participate to regain their driving privileges earlier than otherwise provided) or was left to the court’s discretion and implemented only for repeat offenders. For examples of ignition interlock laws, see 75 Pa.C.S. §§ 88.1-88.8 (Pennsylvania), 90 MGL 24(c)(2) (Massachusetts), and A.R.S. §28-1381(I)(6) (Arizona).
The Evidence:
In a systematic review, Willis et al. reviewed 14 studies in the U.S. and Canada evaluating the effects of ignition interlock programs on drunk-driving recidivism. Willis et al. Alcohol ignition interlock programmes for reducing drink driving recidivism. Cochrane Database of Systematic Reviews. 2004; Issue 3. The underlying studies measured three types of outcomes: (1) recidivism rates while the driver participated in the ignition interlock program, (2) recidivism rates after the ignition interlock device was removed from the vehicle, and (3) recidivism rates during the entire study period. The reviewers found that interlock program participants were less likely to repeat offend than the control group. The impact was even more pronounced for repeat offenders. However, in each instance, recidivism returned to pre-intervention rates after the devices were removed. Though effective as a short term intervention, continued research on the effects of ignition interlock programs on drunk-driving recidivism over longer time periods is needed.
The Bottom Line:
In the judgment of a Cochrane Collaboration expert panel, ignition interlock programs reduce drunk-driving recidivism, but only while the devices are attached.
Additional Information:
Mothers Against Drunk Driving (MADD) maintains an online table listing the states with ignition interlock laws.
Additional Resources: Mothers Against Drunk Driving
Publication Date: 12/07/2009
The Problem:
The operation of motor vehicles while intoxicated is a major public health problem. Each year in the United States roughly 13,400 people die and an additional 255,500 are injured in motor vehicle crashes involving an alcohol-impaired driver. In 2006, these crashes accounted for almost a third of all U.S. traffic-related deaths. CDC: Impaired Driving Factsheet.
The Law:
Blood alcohol per se laws set a blood alcohol limit at which an individual is considered legally impaired (i.e., impairment is “per se” because actual inability to function need not be established). Currently, all states set their BAC limit at 0.08 percent; some previously set the BAC levels at 0.10 percent. For examples of BAC per se laws, see Cal. Veh. Code §23152 (California), Fla. Stat. §316.193 (Florida), K.S.A. §8-1567 (Kansas), M.R.S. §2411 (Maine), N.M. Stat. Ann. §66-8-102 (New Hampshire), N.M. Stat. Ann. §66-8-102 (New Mexico), N.C. Gen. Stat. §20-138.1 (North Carolina), O.R.S. 813.010 (Oregon), Utah Code §41-6a-502 (Utah), 23 V.S.A. §1201 (Vermont), and Va. Code Ann. §18.2-266 (Virginia).
The Evidence:
In a Community Guide systematic review, Shults et al. reviewed nine studies that examined the impact of lowering the BAC limit to 0.08 percent on the rate of alcohol-related motor-vehicle deaths. Shults, et al. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. Am J Prev Med. 2001;21(4S):66-88. According to the reviewers, the underlying studies reveal a considerable association between the adoption of 0.08 percent BAC laws and a decline in alcohol-related motor-vehicle deaths; the median reduction in motor vehicle fatalities after the laws were adopted was 7 percent. Shults et al view these studies as strong evidence of the effectiveness of 0.08 BAC laws as a public health intervention. However, they caution that most of the BAC laws analyzed were enacted along with, or were supplemented by, other preventive drunk-driving laws, such as Administrative License Revocation (ALR) laws, making it difficult to isolate the exact magnitude of the impact of BAC laws.
The Bottom Line:
In the judgment of a Community Guide expert panel, there is strong evidence that laws adopting decreased BAC levels effectively reduce alcohol-related motor-vehicle deaths.
Publication Date: 12/07/2009
The Problem:
The operation of motor vehicles while intoxicated is a major public health problem. Each year in the United States roughly 13,400 people die and an additional 255,500 are injured in motor vehicle crashes involving an alcohol-impaired driver. In 2006, these crashes accounted for almost a third of all U.S. traffic-related deaths. CDC: Impaired Driving Factsheet.
The Law:
At selective breath testing (SBT) checkpoints, law enforcement officials may require a driver to submit to a breath test if the officer has a reasonable suspicion that the driver is intoxicated. As of September 2009, law enforcement agencies in 38 U.S. states and the District of Columbia may conduct sobriety checkpoints. Governors Highway Safety Association. Law enforcement agencies in 11 states are either not authorized by the state to conduct checkpoints or are prohibited from conducting checkpoints by interpretations of state constitutions or by statutes (e.g., Wisconsin, Wis. Stat. § 349.02(2)(a)). Law enforcement officers follow established procedures in conducting checkpoints, including using objective criteria to determine checkpoint locations and using a predetermined system for stopping cars (e.g., every fourth vehicle at a checkpoint is stopped). For examples of laws authorizing checkpoints, see Utah Code Ann. §§ 77-23-101 et seq (Utah) and Nev. Rev. Stat. § 484.359 (Nevada).
The Evidence:
In a systematic review, Shults et al. reviewed 13 studies on SBT checkpoints. Shults, et al. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. Am J Prev Med. 2001;21(4S):66-88. The reviewers found that the use of SBT checkpoints is effective in reducing fatal and nonfatal injuries involved in motor vehicle accidents and in the reduction of total alcohol related crashes. SBT checkpoints were found to reduce fatal and nonfatal injuries during crashes by a median 20 percent. An ancillary benefit noted in the underlying studies of SBT checkpoints is the increased policing of other illegal activity behavior such as driving with a suspended license.
The Bottom Line:
In the judgment of a Community Guide expert panel, there is strong evidence supporting the effectiveness of SBT sobriety checkpoints as a public health intervention aimed at reducing the harms associated with alcohol impaired driving.
Additional Information:
The Community Guide provides online access to a table summarizing the studies used in the review.
The Insurance Institute for Highway Safety provides online access to a table listing statutes and judicial interpretations authorizing or prohibiting sobriety checkpoints.
Additional Resources: The Community Guide , Insurance Institute for Highway Safety
Publication Date: 12/07/2009
The Problem:
The operation of motor vehicles while intoxicated is a major public health problem. Each year in the United States roughly 13,400 people die and an additional 255,500 are injured in motor vehicle crashes involving an alcohol-impaired driver. In 2006, these crashes accounted for almost a third of all U.S. traffic-related deaths. Drivers age 16 to 20 who engage in drunk driving pose an especially dangerous risk to themselves and other motorists. CDC: Impaired Driving Factsheet.
The Law:
All U.S. states currently set the minimum legal drinking age at 21 years (MLDA21). Federal legislation withholds federal highway funds from states that do not adopt an MLDA of 21 years (23 U.S.C. § 158). For examples of MLDA21 laws, see TX Alcoholic Beverage Code § 106.04 (Texas), Conn. Gen. Stat. 30-1(12) and Conn. Gen. Stat. §30-89 (Connecticut).
The Evidence:
Two independent systematic reviews of the relevant studies of this intervention have found a robust association between raising the MLDA to 21 and reductions in alcohol-related crashes. In a Community Guide systematic review, Shults et al. reviewed 33 studies that examined the effect of MLDA21 on fatal and nonfatal crashes likely to have involved alcohol. Shults, et al. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. Am J Prev Med. 2001;21(4S):66-88. Seventeen of the underlying studies evaluated the impact of raising the MLDA to 21, 11 evaluated laws that lowered the MLDA, and remaining 18 used regression analysis to measure changes in both directions. The review found a median reduction in alcohol-related crashes of 17 percent associated with raising the MLDA and a median increase of 8 percent in alcohol-related crashes associated with lowering the MLDA.
Wagenaar and Toomey reviewed 48 studies that measured the impact of MLDA21 on alcohol consumption and reviewed 57 studies that measured the impact of MLDA21 on alcohol-related crashes. Wagenaar, Toomey. Effects of Minimum Drinking age Laws: Review and Analyses of the Literature from 1960 to 2000. Journal of Studies on Alcohol. 2002(14 Suppl):206-25. Across the 48 studies, the authors identified 27 measures finding a statistically significant inverse relationship between MLDA21 and alcohol consumption (8 found a statistically insignificant inverse relationship; 5 found a positive relationship). Some of the measures included, for example, self-reported alcohol consumption and sale of particular alcoholic beverages. Fifty-two measures were indentified finding a statistically significant inverse relation between MLDA21 and crashes (12 found a statistically insignificant inverse relationship; 2 found a positive relationship). These measures included a broad range of types of injuries and crashes outcomes (e.g., nighttime fatal crashes, alcohol-related crashes).
The Bottom Line:
In the judgment of a Community Guide expert panel and the authors of a peer-reviewed systematic study, there is strong evidence to support the effectiveness of MLDA21 as an intervention aimed at reducing alcohol involved motor vehicle crashes.
Additional Information:
The Community Guide provides online access to a table summarizing the results of each study it reviewed.
Additional Resources: The Community Guide
