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There is a growing interest in how extensively the use of marijuana by drivers relates to crash involvement. While cognitive, lab-based studies are consistent in showing that the use of cannabis impairs driving tasks, epidemiological, field-based studies have been inconclusive regarding whether cannabis use causes an increased risk of accidents. There is ample evidence that the presence of cannabis among drivers with a BAC≥0.08g/dL highly increases the likelihood of a motor vehicle crash. Less clear, however, is the contribution of cannabis to crash risk when drivers have consumed very little or no alcohol. This effort addresses this gap in knowledge. We took advantage of a unique database that merged fatal crashes in the California Statewide Integrated Traffic Records System (SWITRS) and the Fatality Analysis Reporting System (FARS), which allows for a precise identification of crash responsibility. To account for recent increase in lab testing, we restricted our sample to cover only the years 1993-2009. A total of 4294 drivers were included in the analyses. Descriptive analyses and logistic regressions were run to model the contribution of alcohol and drugs to the likelihood of being responsible in a fatal crash. We found evidence that compared with drivers negative for alcohol and cannabis, the presence of cannabis elevates crash responsibility in fatal crashes among drivers at zero BACs (OR=1.89) and with 0BAC0.05g/dL (OR=3.42), suggesting that emphasis on curbing impaired driving should not be solely focused on heavy-drinking drivers. Data limitations however caution about the generalizability of study findings. Special efforts to understand the effect of cannabis on fatal crashes, in particular in the absence of alcohol, are needed.

Research measuring levels of enforcement has investigated whether increases in police activities (e.g., checkpoints, driving-while-intoxicated [DWI] special patrols) above some baseline level are associated with reduced crashes and fatalities. Little research, however, has attempted to quantitatively measure enforcement efforts and relate different enforcement levels to specific levels of the prevalence of alcohol-impaired driving.The objective of this study was to investigate the effects of law-enforcement intensity in a sample of communities on the rate of crashes involving a drinking driver. We analyzed the influence of different enforcement strategies and measures: (1) specific deterrence - annual number of driving-under-the-influence (DUI) arrests per capita; (2) general deterrence - frequency of sobriety checkpoint operations; (3) highly visible traffic enforcement - annual number of traffic stops per capita; (4) enforcement presence - number of sworn officers per capita; and (5) overall traffic enforcement - the number of other traffic enforcement citations per capita (i.e., seat belt citations, speeding tickets, and other moving violations and warnings) in each community.We took advantage of nationwide data on the local prevalence of impaired driving from the 2007 National Roadside Survey (NRS), measures of DUI enforcement activity provided by the police departments that participated in the 2007 NRS, and crashes from the General Estimates System (GES) in the same locations as the 2007 NRS. We analyzed the relationship between the intensity of enforcement and the prevalence of impaired driving crashes in 22-26 communities with complete data. Log-linear regressions were used throughout the study.A higher number of DUI arrests per 10,000 driving-aged population was associated with a lower ratio of drinking-driver crashes to non-drinking-driver crashes (p=0.035) when controlling for the percentage of legally intoxicated drivers on the roads surveyed in the community from the 2007 NRS. Results indicate that a 10% increase in the DUI arrest rate is associated with a 1% reduction in the drinking driver crash rate. Similar results were obtained for an increase in the number of sworn officers per 10,000 driving-age population.While a higher DUI arrest rate was associated with a lower drinking-driver crash rate, sobriety checkpoints did not have a significant relationship to drinking-driver crashes. This appeared to be due to the fact that only 3% of the on-the-road drivers were exposed to frequent sobriety checkpoints (only 1 of 36 police agencies where we received enforcement data conducted checkpoints weekly). This low-use strategy is symptomatic of the general decline in checkpoint use in the U.S. since the 1980s and 1990s when the greatest declines in alcohol-impaired-driving fatal crashes occurred. The overall findings in this study may help law enforcement agencies around the country adjust their traffic enforcement intensity in order to reduce impaired driving in their community.

BACKGROUND: Young adulthood (ages 18-25 years) represents a time when high-risk behaviors, including alcohol and drug use, peak. Electronic music dance events (EMDEs) featured at clubs provide an ecologic niche for these high-risk behaviors. PURPOSE: This paper examines the prevalence of alcohol and drug use among EMDE patrons. Examination of personal characteristics associated with exit levels of alcohol and drug use identifies important indicators of risk taking for prevention strategies. METHODS: Data were collected anonymously during 2010-2012 from 2028 patrons as they entered and exited clubs in the San Francisco Bay area featuring EMDEs. Nearly half were aged ≤25 years. Biological measures of drug and alcohol and self-reported personal characteristics were attained. Analyses were completed in 2012. RESULTS: At entrance, more than one fifth of patrons were positive for drug use and one fourth arrived either impaired (blood alcohol concentration [BAC]: 0.05%-0.079%) or intoxicated (BAC: >0.08%) by alcohol. At exit, one fourth tested positive for drugs, and nearly half were impaired or intoxicated by alcohol. Individual characteristics that were important for levels of risk included prior alcohol use behaviors, sexual identity, ethnic/racial identity, and transportation to the event. Gender did not differentiate for alcohol use but fewer women used drugs. CONCLUSIONS: Findings confirm the importance of targeting EMDEs for prevention efforts. EMDEs attract young working adults who are engaged in heavy alcohol and/or drug use. Targeting these social settings for delivering public health prevention strategies regarding alcohol and drug use and related harm is indicated by the findings. Language: en

BACKGROUND: Clubs that feature electronic music dance events (EMDEs) draw young adults aged 18-34 who are at high-risk for alcohol-related crashes to locations where alcohol sales are the principal source of revenue. Up to 30% of these attendees may also use drugs. This provides an important context in which to study driving arrangements that reflect concern with impaired driving. We explored whether drivers were using less alcohol and fewer drugs at exit than their passengers were and whether a driver for the group ever changed after consuming too much during the evening. METHODS: Using biological measures of alcohol consumption (breath tests) and drug use (oral fluid tests), 175 drivers and 272 passengers were surveyed among young adults arriving at and departing from EMDEs in San Francisco. RESULTS: Upon exit from the drinking locations, only 20% of the drivers, compared to 47% of the passengers, had a high breath alcohol concentration (defined as a BrAC of .05g/dL or greater). Further, there was evidence that drivers with high BrACs switched to passenger status on exit and former passengers with lower BrACs replaced those drivers. However, there were no differences in the prevalence of drug use among drivers and passengers. CONCLUSIONS: These findings suggest that the effort by young adult drivers to avoid alcohol-impaired driving appears to be reducing the number of drivers with high BrACs returning from drinking locations, such as EMDEs, by about one third. However, there is no similar pattern for drugged driving. Language: en

Background Studies of drinking drivers in alcohol-related crashes have shown that high breath-alcohol concentrations (BrACs) are associated with illegal drug use. Until the 2007 National Roadside Survey (NRS), the prevalence of drugs among drinking drivers on U.S. roads was unknown. Using NRS data, we explore how many drivers with positive BrACs may also be using drugs and their significance to current drinking-driving enforcement procedures. Methods Based on a stratified, random sample covering the 48 U.S. contiguous states, we conducted surveys on weekend nights from July–November 2007. Of the 8384 eligible motorists contacted, 85.4% provided a breath sample; 70.0%, an oral fluid sample; and 39.1%, a blood sample. We conducted regression analyses on 5912 participants with a breath test and an oral fluid or blood test. The dependent variables of interest were illegal drugs (cocaine, cannabinoids, street drugs, street amphetamines, and opiates) and medicinal drugs (prescription and over-the-counter). Results 10.5% of nondrinking drivers were using illegal drugs, and 26 to 33% of drivers with illegal BrACs (≥0.08 g/dL) were using illegal drugs. Medicinal drug use was more common among nondrinking drivers (4.0%) than among drivers with illegal BrACs (2.4%). Conclusions The significant relationship between an illegal BrAC and the prevalence of an illegal drug suggests as many as 350,000 illegal drug-using drivers are arrested each year for DWI by U.S. alcohol-impaired driving enforcement. These drug-using drivers need to be identified and appropriate sanctions/treatment programs implemented for them in efforts to extend per se laws to unapprehended drug users.

INTRODUCTION: The high crash rate of youthful novice drivers has been recognized for half a century. Over the last decade, graduated driver licensing (GDL) systems, which extend the period of supervised driving and limit the novice's exposure to higher-risk conditions (such as nighttime driving), have effectively reduced crash involvements of novice drivers. METHOD: This study used data from the Fatality Analysis Reporting System (FARS) and the implementation dates of GDL laws in a state-by-year panel study to evaluate the effectiveness of two key elements of GDL laws: nighttime restrictions and passenger limitations. RESULTS: Nighttime restrictions were found to reduce 16- and 17-year-old driver involvements in nighttime fatal crashes by an estimated 10% and 16- and 17-year-old drinking drivers in nighttime fatal crashes by 13%. Passenger restrictions were found to reduce 16- and 17-year-old driver involvements in fatal crashes with teen passengers by an estimated 9%. CONCLUSIONS: These results confirm the effectiveness of these provisions in GDL systems. Impact on Public Health. States without the nighttime or passenger restrictions in their GDL law should strongly consider adopting them. IMPACT ON INDUSTRY: The results of this study indicate that nighttime restrictions and passenger limitations are very important components of any GDL law. Keywords: Driver distraction; Language: en

A systematic review of the literature to assess the effectiveness of ignition interlocks for reducing alcohol-impaired driving and alcohol-related crashes was conducted for the Guide to Community Preventive Services (Community Guide). Because one of the primary research issues of interest--the degree to which the installation of interlocks in offenders' vehicles reduces alcohol-impaired driving in comparison to alternative sanctions (primarily license suspension)--was addressed by a 2004 systematic review conducted for the Cochrane Collaboration, the current review incorporates that previous work and extends it to include more recent literature and crash outcomes. The body of evidence evaluated includes the 11 studies from the prior review, plus four more recent studies published through December 2007. The installation of ignition interlocks was associated consistently with large reductions in re-arrest rates for alcohol-impaired driving within both the earlier and later bodies of evidence. Following removal of interlocks, re-arrest rates reverted to levels similar to those for comparison groups. The limited available evidence from three studies that evaluated crash rates suggests that alcohol-related crashes decrease while interlocks are installed in vehicles. According to Community Guide rules of evidence, these findings provide strong evidence that interlocks, while they are in use in offenders' vehicles, are effective in reducing re-arrest rates. However, the potential for interlock programs to reduce alcohol-related crashes is currently limited by the small proportion of offenders who participate in the programs and the lack of a persistent beneficial effect once the interlock is removed. Suggestions for facilitating more widespread and sustained use of ignition interlocks are provided.

Introduction The effectiveness of ignition interlocks at reducing drunk driving has been limited by the ability of driving-while-intoxicated (DWI) offenders to avoid court orders to install the devices. Methods In a pilot program in New Mexico, four Santa Fe County judges imposed home confinement (via electronic monitoring bracelets) on offenders who claimed to have no car or no intention to drive. Interlock installation rates for Santa Fe County were compared with all other counties in New Mexico over a 2-year program and 2-year post-program period. Results During the two program years, 70% of the drivers convicted of DWI in Santa Fe County installed interlocks, compared to only 17% in the other counties, but when the program was terminated, the Santa Fe installation rate fell by 18.8 percentage points. Summary Mandating the alternative sanction of house arrest led to the highest reported interlock installation rate for DWI offenders. Impact on Industry Impaired driving is a substantial expense to employers, particularly when it bars driving that interferes with employment. Interlocks provide a method of protecting the public while permitting the offender to drive sober. This study was directed at increasing interlock use by DWI offenders.

The role of age (youth and driving inexperience) and alcohol as major risk factors in traffic crash causation has been firmly established by numerous studies over the past 50 years. Less well established is how the two variables interrelate to influence crash risk. Some investigations have hypothesized an interactive or synergistic effect in which young drivers with less experience and a greater tendency to take risks are more adversely affected at lower blood alcohol concentrations (BACs) than are older drivers. The evidence for this hypothesis is mixed. Resolution of this issue has important implication for developing countermeasures directed at the young driver crash problem.Case control data previously collected in Long Beach and Fort Lauderdale were reanalyzed using a more sensitive method for detecting interaction effects than used in the original analysis. A conditional logistic regression analyses found a highly significant agexBAC interaction (P.0001) involving differences between drivers under 21 and those 21 and older.The results clearly indicate that positive BACs in drivers under 21 are associated with higher relative crash risks than would be predicted from the additive effect of BAC and age. It is likely that two mechanisms are operating to cause the interaction. First, it seems likely that the crash avoidance skill of young novice drivers would be more adversely affected by alcohol due to their driving inexperience, immaturity, and less experience with alcohol. Second, drivers under 21 who choose to drink and to drive after drinking probably have pre-existing characteristics that predisposed them to risk taking and crash involvement apart from any increased vulnerability to alcohol impairment.The results support increased enforcement of zero-tolerance BAC laws for minors.

There is an increasing number of motor vehicle crashes (MVCs) in the U.S. that occur at intersections. Noncompliance with traffic signals is one of the causes for such increase. In this study, we focused on Hispanic drivers. It has been shown that failing to follow traffic laws and regulations is a major cause of MVCs in Latin America. Does this driving behavior in Latin America correspond to the Hispanic community in the U.S.? Are U.S. Hispanics more likely to die in a red light incident? Are Hispanics more likely to be red light runners than other racial/ethnic groups in the U.S.? We answered these questions by taking advantage of a 1990-1996 Fatality Analysis Reporting System (FARS) file with additional racial/ethnic information. Overall, we found no differences between African-American, White, and Hispanic drivers regarding red light running. We found that drinking and driving was the most important factor for red light running. However, we found evidence that some Hispanic subgroups may be more vulnerable to red light running. One such subgroup is formed by Hispanics who have no valid driver license and no record of previous driver license suspension. This study is the first to apply national, archival data to document the relevance of race/ethnicity to the red light running problem, and we hope that it might serve as an incentive for more research on this area.

More than a dozen studies on the effectiveness of the .08 blood alcohol concentration (BAC) laws have been published; however, those studies have varied both in the statistical methods and the type of outcome measure used, so it is difficult to integrate the findings into an overall estimate of the effectiveness of the law. This study used a consistent outcome measure, drinking drivers in fatal crashes and an identical methodology time-series analysis, to analyze the introduction of the .08 law in 18 states and the District of Columbia from 1982 to 2000. Each analysis accounted for other key safety laws (administrative license suspension/revocation and safety belt laws), as well as economic conditions that might influence the effectiveness of the .08 law. This provided 19 independent evaluations in which the effectiveness (treatment effect) of the law could be measured in the same quantitative terms. The number of drinking drivers in fatal crashes declined in 16 of the 19 jurisdictions after the .08 law was adopted. Nine of the 16 reductions were statistically significant (p < .05). The effect size combined across all 19 locations showed statistically significant decline (p < .005) of 14.8% in the rate of drinking drivers in fatal crashes after the .08 laws were introduced. The reduction was greater in states that had an administrative license suspension/revocation law and implemented frequent sobriety checkpoints. This analysis suggests that 947 lives might have been saved, had all 50 states and the District of Columbia had the .08 law throughout the year 2000.

The objective of this research was to determine the extent to which the decline in alcohol-related highway deaths among drivers younger than age 21 years can be attributed to raising the minimum legal drinking age (MLDA) and establishing zero tolerance (0.02% blood alcohol concentration (BAC) limit for drivers younger than age 21 years) laws. Data on all drivers younger than age 21 years involved in fatalities in the United States from 1982 to 1997 were used in the study. Quarterly ratios of BAC-positive to BAC-negative drivers in each of the 50 states where analyzed in a pooled cross-sectional time-series analysis. After accounting for differences among the 50 states in various background factors, changes in economic and demographic factors within states over time, and the effects of other related laws, results indicated substantial reductions in alcohol-positive involvement in fatal crashes were associated with the two youth-specific laws. The policy of limiting youth access to alcohol through MLDA laws and reinforcing this action by making it illegal for underage drivers to have any alcohol in their system appears to have been effective in reducing the proportion of fatal crashes involving drinking drivers.

This paper examines the correlates and predictors of driving under the influence behaviors (DUIBs) during the past month by college students. Measures of heavy episodic drinking, monthly drinking frequency, monthly drinking variance, monthly drinks per occasion and reported marijuana use are compared as predictors net of other predictive factors. A cross-sectional telephone survey was conducted with college students by a university social science research laboratory. Respondents attended two large public universities located in the southwestern part of the US. Participants included 803 randomly selected college students. The interview schedule included items from the Core Alcohol and Drug Survey and the College Alcohol Risk Assessment Guide. Several additional last-drinking-event items were also developed for the interview. Bivariate analyses indicate that marijuana use (past year), heavy episodic drinking, reports of DUIBs (driving under the influence or riding with a driver who is under the influence) in the past year, monthly frequency of drinking, the average number of drinks consumed when drinking and age are correlates of DUIBs during the past month. Multivariate analyses indicate past year DUIBs, monthly frequency of drinking and monthly marijuana use predicted recent DUIB.

Problem: It is estimated that at least 75% of suspended or revoked drivers continue to drive illegally. In states like California, there are also a substantial and growing number of people who drive without ever having been licensed. Some states, such as Ohio and California, have enacted vehicle impoundment and forfeiture programs as sanctions to reduce these offenses. Published evaluations indicate that vehicle impoundment laws reduce recidivism and crash rates. However, vehicle forfeiture programs have been less successful, mostly because of low levels of enforcement. Method: Police officers and district attorneys from 17 jurisdictions were interviewed by phone or in person to determine current enforcement levels and impediments to more aggressive application of statutory authority. Results and discussion: The survey found that most California jurisdictions are enforcing vehicle impoundments for first-time offenders. However, very few jurisdictions were enforcing the vehicle forfeiture law for repeat offenders. Among the reasons for not enforcing the vehicle forfeiture law was a perception that it was too time-consuming and/or not a priority among prosecutors. However, a number of authorities indicated that the simple vehicle impoundment procedure is often functionally equivalent to forfeiture because many drivers fail to retrieve the vehicle at the end of the impoundment period. Impact on industry: Vehicle impoundment programs are effective mechanisms in deterring illicit driving, and states should be encouraged to initiate vehicle impoundment laws. States could achieve even greater safety benefits if vehicle forfeiture sanctions were extensively used for repeat offenders. However, based on California's experience, the incremental benefits of vehicle forfeiture (over vehicle impoundment) may not be very great.

License suspension effectively reduces recidivism and crash involvement of those convicted of driving while impaired (DWI). The impact of this sanction, however, is being reduced by the large number of offenders (up to 75%) who drive even though suspended. To deal with this problem. several states have enacted laws providing for vehicle impoundment, immobilization, or forfeiture for repeat DWI offenders and for driving while suspended (DWS) offenders. Although a 1992 review of vehicle sanctions for DWI and DWS offenders showed 32 states with such laws, they were infrequently applied. Further, none of those laws had been adequately evaluated. This paper reviews the studies of vehicle action programs in California, Minnesota, New York, Ohio, Oregon, and Washington that have been applied broadly enough to permit evaluation. Although none of the studies has applied random assignment to ensure equal groups. several have applied sufficient statistical controls to provide reasonably credible results. All the programs reviewed showed positive effects. including some relatively large recidivism reductions, from denying offenders the use of their vehicles for 1-6 months. Highlighted in this review are several issues that appear to be important to the effectiveness of vehicle sanctioning programs.

Lowering state blood alcohol concentration (BAC) limits to 0.08, though controversial, has been supported by most evaluation studies to date. The Illinois .08 BAC law implemented in 1997 provided a unique opportunity to evaluate the effect of the law without the simultaneous passage of an administrative license revocation (ALR) law, which has clouded some previous evaluations of the .08 laws. The proportion of all drinking drivers in fatal crashes was compared before versus after implementing the .08 law using time-series analysis to evaluate 12 years of fatal crash data for Illinois and five bordering states. The results showed that the proportion of drinking drivers in fatal crashes decreased by 14% in Illinois and increased by 3% in bordering states. The proportion of drinking drivers in fatal crashes in Illinois, though increasing since 1995, was sharply reduced after passage of the .08 law in 1997, saving more than 100 lives in 1998 and 1999 than it would have without the .08 law.

Problem: Universities have a major problem with binge drinking by students. This problem is greater for universities near national borders where underage students can cross into areas where the legal drinking age is younger than in the United States. Method: A telephone survey of students at two large universities, within an hour drive of the Mexican border, was conducted to determine the extent of the cross-border drinking problem. Results: On average, the students reported about 6.5 trips across the border to drink in the past year and indicated that when drinking in Mexico they consumed greater amounts of alcohol — more than six drinks compared to 4.5 in the United States. Summary: The study indicated that young males drank the most (8.7 drinks) when in Mexico compared to 4.7 drinks for those older than 21 years and 4.5 drinks for women younger than 21 years. Thus, young male students who are more likely to be drivers than their female comparisons drink twice as much, when in Mexico, creating a significant risk for both. Impact on Industry: Unknown, but companies near the border may wish to consider special education programs aimed at underage male employees.

This paper presents an analysis of the relationships between the passage of key alcohol safety laws and the number of drinking drivers in fatal crashes. The study evaluated three major alcohol safety laws--administrative license revocation laws, 0.10 illegal per se, and 0.08 illegal per se laws--on the proportion of drinking drivers in fatal crashes. Drivers aged 21 and older in fatal crashes at two BAC levels--0.01-0.09 and 0.10 or greater--were considered separately. Drivers under age 21 were not included because they are affected by the Minimum Legal Drinking Age (MLDA) law. This study used data on drinking drivers in fatal crashes from the Fatality Analysis Reporting System (FARS) covering 16 years (1982-1997) for all 50 states and the District of Columbia. Also included in the study were such variables as per capita alcohol consumption and annual vehicle miles traveled (VMT), which could affect the number of alcohol-related crashes. The results indicate that each of the three laws had a significant relationship to the downward trend in alcohol-related fatal crashes in the United States over that period. This paper points out that this long-term trend is not the product of a single law. Instead, it is the result of the growing impact of several laws over time plus the affect of some factors not included in the model tested (such as the increasing use of sobriety checkpoints and the media's attention to the drinking-and-driving problem).

Tijuana's loosely enforced age-18 drinking limit and low-priced alcohol entices thousands of young Americans to drink. On two weekends in 1997 and 1998, the Mexican government held elections during which alcohol sales were prohibited from midnight Friday night through 10 a.m. Monday. This study reports the effects of the election closings. To detect changes on two election nights, we analyzed the Immigration and Naturalization Service (INS) counts and random breath tests of U.S. residents returning from Tijuana. The total prohibition against liquor sales on election Saturday nights was associated with a 71.2% reduction in total pedestrian returnees and a 34.5% reduction on Friday nights with partial closing of bars. Further, results showed that the number of pedestrians with breath alcohol contents (BACs) at 0.08 or higher was reduced during election days. The closing of Tijuana's alcohol establishments reduced the number of border crossers and the BACs of returnees.

This analysis examines whether roadside surveys that measure changes in the prevalence of driving after drinking can be used to evaluate the impact of interventions designed to reduce alcohol-related traffic crashes. Using data collected at a roadside survey over a 4-year period in two California communities (N = 33,614), this analysis examines the relationship of BAC and drinks since 5 P.M., aggregated on a monthly basis, with nighttime injury crash data from the California Highway Patrol aggregated on a monthly basis. A regression analysis was used in which daytime injury and drinking style were covariates. The data demonstrate that temporal changes in drinking and driving collected at a roadside survey reflect temporal changes in nighttime injury rates. Hence, this study substantiates the use of roadside surveys as an appropriate methodology to evaluate drinking and driving interventions.

This report covers an evaluation of programs designed to reduce unlawful driving in the states of Washington and Oregon by providing for the marking of the license plate of a vehicle when its operator was apprehended driving while suspended. In both states, the records of 101,000 drivers convicted of a drunk-driving offense who were potentially at risk for this sanction were analyzed using time series analysis to determine the general deterrent effect of the law. In addition, the specific deterrent effect of having one's vehicle marked was studied in Oregon using analysis of covariance. Results of these analyses indicated that the law had both a general and specific deterrence effect in Oregon but no measurable effect in Washington.

Driving while suspended is a growing problem in most states. To deal with this problem, a number of jurisdictions are impounding and/or immobilizing the vehicles of driving while suspended or multiple driving under the influence offenders. This study evaluates the first 2 years of the implementation of this type of law in Franklin County (Columbus), OH. Variations in police enforcement and judicial sentencing policies resulted in some offenders, though eligible for impoundment or immobilization, not receiving the sanction. The recidivism rates of these offenders were compared with offenders who did receive a vehicle sanction. Tracking these two groups of offenders for up to 2 years demonstrated that the offenders who received the sanction had lower recidivism rates, both before and after they reclaimed their vehicles.

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). This reprinted article has been retracted at the request of the Publisher. The online version of this reprint has been withdrawn as it was a redundant duplicate of the original article. The Publisher apologizes for any inconvenience this may cause.

This critique refutes Zador's claim [1976] that Alcohol Safety Action Projects, as large scale social programs have been ineffective. The discussion takes issue with Zador's comparison groups, statistical design, statistical methods, and use of 12-month fatality totals for data analysis. In addition to weaknesses and deficiencies in these areas, the authors find Zador's conclusion unfounded based on the analysis presented.

The effectiveness of drunk driving enforcement patrols is generally assumed. However, few adequate evaluations are available in the traffic safety literature. The U.S. Department of Transportation funded a special program in Stockton, a city with a population of 120,000 in the central valley of California, to test the effectiveness of special drunk driving patrols on weekend evenings, applied within a setting in which no other major alcohol safety programs were present. The objective of this effort was to determine the effectiveness of a "traditional" approach to enforcing driving while impaired (DWI) laws; one in which innovative procedures such as sobriety checkpoints were not used. The results indicated that nighttime collisions in Stockton were reduced during the three and a half year period of the special enforcement program.