Identifying factors that predict persistent driving after drinking,unsafe driving after drinking,and driving after using cannabis among young adults

The main aim of this study was to identify adolescent/young adulthood factors that predicted persistent driving after drinking, persistent unsafe driving after drinking, and persistent cannabis use and driving among young adults. It was a longitudinal study of a birth cohort (n=933, 474 males and 459 females) and was based on data collected at ages 15, 18, 21 and 26 years. At each of these ages members of the cohort attended the research unit for a personal interview by a trained interviewer, using a standardised questionnaire. For this study, the data for the outcome measures (persistent driving after drinking, persistent unsafe driving after drinking, and persistent driving after using cannabis) were obtained at ages 21 and 26 years. The main explanatory measures were collected at ages 15, 18, 21 years and included demographic factors (academic qualifications, employment, parenting); personality measures; mental health measures (substance use, cannabis dependence, alcohol dependence, depression); anti-social behaviour (juvenile arrest, aggressive behaviour, court convictions); early driving behaviour and experiences (car and motorcycle licences, traffic crashes).The analyses were conducted by gender. The results showed that females who persisted in driving after drinking (13%, n=61) were more likely than the others to have a motorcycle licence at 18. The males who persisted in driving after drinking (28%, n=135) were more likely than the other males to have some school academic qualifications and to be employed at age 26. Compared to the other males, those who persisted in unsafe driving after drinking (4%, n=17) were more likely to be aggressive at 18 and alcohol dependent at 21. Only six (1%) females persisted in unsafe driving after drinking so regression analyses were not conducted for this group. For persistent driving after using cannabis, the univariate analyses showed that females who persisted with this behaviour tended to have high substance use at 18, cannabis dependence at 21, police contact as a juvenile, and to be a parent at 21. For this group, because of the small numbers (3%, n=13) multivariate analyses were not appropriate. For the males who persisted in driving after using cannabis (14%, n=68) a wide range of variables were significant at the univariate stage. The multivariate analysis showed that the most important factors were dependence on cannabis at 21, at least one traffic conviction before 21, a non traffic conviction before 18, and low constraint at 18. CONCLUSION: These results show different characteristics were associated with persistence in each of these outcome behaviours. This indicates that different approaches would be required if intervention programmes were to be developed to target these behaviours.     

Youth, alcohol and relative risk of crash involvement

Deaths and injuries due to road-crash involvement are a major health and safety problem, especially among youth. Numerous factors can account for the overrepresentation of young drivers in road crashes and one of these--alcohol--has received renewed attention. This paper examines evidence pertaining to drinking and driving among youth to determine the extent to which alcohol has special significance for crashes involving young drivers. Three sets of studies are reviewed: those providing data on the extent of drinking and drinking-driving among youth, those that examine alcohol use among youth involved in road crashes and those that estimate the relative risk of a road crash for young drinking drivers. Findings show that frequent and heavy alcohol consumption among teenagers and young adults is not unusual, although they are less likely than older age groups to drive after drinking. Nonetheless, those young people who drive after drinking have a greater risk of crash involvement than older drinking drivers at all blood alcohol concentrations. One explanation of this finding assumes that young people are "inexperienced" with drinking and with driving. Limited behavioural research done to date supports some but not all assumptions implicit in this reasoning. There is also evidence in favour of an alternative hypothesis, namely, that the comparatively higher crash-risk among young drinking drivers is attributable to a subset of this group, those that engage in risky driving behaviour and who also happen to use alcohol. Further investigation into the personal and social characteristics of young people who drive after drinking would provide a sounder empirical basis for policies and programmes to reduce crash involvement among youth.     

Influences during adolescence on perceptions and behaviour related to alcohol use and unsafe driving as young adults

OBJECTIVE: To investigate whether aggression, parent and peer influences, and previous traffic-related experiences at ages 15 and 18 impacted on (a) differences between the perceived safe and estimated legal alcohol consumption limit, and (b) driving while impaired (DWI) behaviour at age 21. METHOD: The study population was a birth cohort involved in a longitudinal investigation of health and development. At the ages of 15 and 18, study members completed questionnaires assessing parent and peer attachment, experience travelling with an alcohol impaired adult or youth, aggression, and previous crash experience. At age 21, study members were questioned about how much alcohol they perceived they could drink and still drive safely, and whether they had driven after 'perhaps consuming too much alcohol'. For each participant their legal alcohol consumption limit was estimated using their height and weight. Path analysis was used to determine whether variables measured at ages 15 and 18 predicted differences between the perceived safe and estimated legal alcohol consumption limit and driving while impaired, both measured at age 21. RESULTS: Insufficient females drove while impaired at age 21, who also had complete data on all other variables, to conduct path analysis for this outcome. For males, aggression at ages 15 and 18, travelling with an impaired youth at age 18, and previous crash experience at age 18 predicted DWI behaviour at age 21. Only aggression at age 15 predicted the difference between perceived safe and estimated legal alcohol consumption limit for the males. For females, aggression at ages 15 and 18, and travelling with an impaired adult at age 15 predicted the difference between perceived safe and estimated legal alcohol consumption limit. CONCLUSION: The results show that aggressive behaviours and adult and/or youth modelling of drink driving behaviours in mid- to late-adolescence are related to differences between perceived safe and estimated legal alcohol consumption limit for both genders and driving while impaired for males.     

Trends in alcohol-impaired driving in Canada

While a general decreasing trend in the number of persons killed in a traffic crash involving a drinking driver has occurred in Canada since the 1980s, it is evident that much of this decrease occurred in the 1990s. Since 2002, less progress has been made as the number of persons killed in crashes involving drinking drivers remains high. To better understand the current situation, this paper describes trends in drinking and driving in Canada from 1998 to 2011 using multiple indicators based on data collected for the Traffic Injury Research Foundation's (TIRF) Road Safety Monitor (RSM), the National Opinion Poll on Drinking and Driving, and trends in alcohol-related crashes based on data collected for TIRF's national Fatality Database in Canada. There has been a continued and consistent decrease in the number of fatalities involving a drinking driver in Canada. This remains true when looking at the number of fatalities involving a drinking driver per 100,000 population and per 100,000 licensed drivers. This decreasing trend is also still apparent when considering the percentage of persons killed in a traffic crash in Canada involving a drinking driver although less pronounced. Data from the RSM further show that the percentage of those who reported driving after they thought they were over the legal limit has also declined. However, regardless of the apparent decreasing trend in drinking driving fatalities and behaviour, reductions have been relatively modest, and fatalities in crashes involving drivers who have consumed alcohol remain high at unacceptable levels.     

Retail alcohol monopolies, underage drinking, and youth impaired driving deaths

OBJECTIVE: To explore associations of state retail alcohol monopolies with underage drinking and alcohol-impaired driving deaths. DATA: Surveys on youth who drank alcohol and binge-drank recently and their beverage choices; census of motor vehicle fatalities by driver blood alcohol level. METHODS: Regressions estimated associations of monopolies with under-21 drinking, binge drinking, alcohol-impaired driving deaths, and odds a driver under 21 who died was alcohol-positive. RESULTS: About 93.8% of those ages 12-20 who consumed alcohol in the past month drank some wine or spirits. In states with a retail monopoly over spirits or wine and spirits, an average of 14.5% fewer high school students reported drinking alcohol in the past 30 days and 16.7% fewer reported binge drinking in the past 30 days than high school students in non-monopoly states. Monopolies over both wine and spirits were associated with larger consumption reductions than monopolies over spirits only. Lower consumption rates in monopoly states, in turn, were associated with a 9.3% lower alcohol-impaired driving death rate under age 21 in monopoly states versus non-monopoly states. Alcohol monopolies may prevent 45 impaired driving deaths annually. CONCLUSIONS: Continuing existing retail alcohol monopolies should help control underage drinking and associated harms.     

Impact of age at onset of cannabis use on cannabis dependence and driving under the influence in the United States

Background and aims

There is growing evidence that driving under the influence of cannabis is associated with a higher risk of motor vehicle crash. Cannabis dependence has been reported to be associated with a three-fold increased risk of motor vehicle crash. The impact of the age at onset of cannabis use on the risk of both cannabis dependence and driving under the influence of cannabis has not been evaluated so far.

Methods

Data were drawn from the 2001–2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a survey of 43,093 adults aged 18 years and older. We limited our analyses to the sample of participants who reported having ever used cannabis (n = 8172), of whom 8068 had a known age at onset of cannabis use.

Results

Of the 8068 participants included, 5.15% reported having driven under the influence of cannabis. Among those, only a minority (14.46%) were diagnosed with cannabis dependence.Compared to those who start using cannabis at age 21 years or after, participants who used cannabis before the age of 14 years were 4 times more likely to have a history of cannabis dependence and 3 times more likely to reported having driven under the influence of cannabis. An inverse relationship between the age at onset of cannabis use and driving under the influence and risk of cannabis dependence was found.

Conclusions

Starting to smoke cannabis younger than 21 years is associated with both cannabis dependence and driving under the influence of cannabis.     

The burden of road trauma due to other people's drinking

The purpose of this study was to estimate the burden of road traffic injury due to alcohol consumption by someone other than the injured party. We estimated the number and proportion of these traffic deaths and non-fatal traffic injuries, and the associated social costs, for a five-year period (2003–2007) in New Zealand. We found that more than 40% of alcohol-related crash injuries in New Zealand are suffered by people who have not themselves been drinking. While the rate of road traffic injuries and the involvement of alcohol peak amongst young adults, so too does the proportion of all road traffic crash injuries that are due to other people's drinking, reaching one in five in the 15–19-year age group. Most innocent victims are car passengers, and this includes almost all children who are injured by drink driving. For a large majority of the children injured, the driver affected by alcohol is the driver of their own car. Using official cost figures, alcohol-related injuries to innocent victims cost the country more than half a billion dollars per year.     

An exploratory study of the relationship between road rage and crash experience in a representative sample of US drivers

The phenomenon of road rage has been frequently discussed but infrequently examined. Using a representative sample of 1382 US adult drivers, who were interviewed in a 1998 telephone survey, exploratory analyses examined the relationship between self-reported measures of road rage, generally hazardous driving behaviors, and crash experience. Regarding specific road rage behaviors, most respondents reported having engaged in verbal expressions of annoyance; however only 2.45% reported ever having been involved in direct confrontation with another car or driver. After controlling for gender, age. driving frequency, annual miles driven and verbal expression, an angry/threatening driving subscale of road rage was significantly associated with hazardous driving behaviors that included frequency of driving over the legal blood alcohol limit, receipt of tickets in the past year. and habitually exceeding the speed limit as well as crash experience. However, the verbal/frustration expression subscale was not associated with crash experience or hazardous driving indicators, except for number of tickets, after controlling for other crash-related factors such as gender and age. Direct confrontation by deliberately hitting another car or leaving the car to argue with and/or injure another driver was rarely reported. Results suggest that angry/threatening driving is related to crash involvement; however, after controlling for exposure and angry/threatening and hazardous driving the relationship of milder expressions of frustration while driving and crash involvement was not significant.     

Young male drinkers and impaired driving intervention: Results of a U.S. telephone survey

The present study examines the role of interveners in the driving behavior of a group of drivers at higher risk for involvement in a fatal, alcohol-related motor vehicle accident than the general population, based on their demographic characteristics. The sample consisted of men, aged 21–34 years, living in areas where alcohol-involved motor vehicle fatalities most commonly occur. More than one-half (55%) of these men reported having been the target of an intervention to prevent them from drinking and driving. The variables most strongly associated with having been the target of an intervention were: involvement in an accident after drinking; frequency of driving after drinking too much to drive safely; binge drinking; reporting that it takes ten or more drinks to feel drunk. Age, total alcohol consumption and the relationship between the target and the intervener predicted intervention success. Persons who have close relationships with drinking drivers, particularly wives/girlfriends, are most likely to be successful in preventing these men from drinking and driving. To the extent they can be encouraged to safely intervene, wives/girlfriends and close friends may be potential targets for messages promoting informal social control of drinking and driving.     

Unsafe motor vehicle practices among substance-using college students

This study examines the relationship between substance use and behaviors that increase the risk for motor vehicle crashes and crash-related injuries. The investigation uses National College Health Risk Behavior Survey data collected in 1995 by the Centers for Disease Control and Prevention. These data are representative of 2- and 4-year undergraduate college students in private and public colleges and universities in the United States. Smokers, episodic heavy drinkers, marijuana users and users of illegal drugs in combination with alcohol were significantly more likely to drive after drinking alcohol and ride with a driver who had been drinking alcohol and significantly less likely to wear safety belts while driving or while riding in a car as a passenger. This study indicates that college students who are substance users are more likely to behave in a manner which increases their risk for motor vehicle crashes and motor vehicle crash injuries.     

What do Israeli Jewish and Arab adolescents know about drinking and driving?

This article describes a study, which is the first in Israel to investigate knowledge concerning drinking and driving among a large group of 2408 adolescents of four religions in the north of Israel, in the winter of 1995. The article analyses the results by referring to general scores and to five areas in the “drinking and driving” domain: legal blood alcohol concentration (BAC) limit, minimal number of drinks prohibited by the law before driving, common myths, main effects of alcohol on driving ability and youth vulnerability. The article emphasizes differences between the Jewish group and the non-Jewish (Arab) group. The average score of the sample was 2.06 (out of 5). Jews received the highest score (2.30) and Moslems got the lowest score (1.45). No differences were found among those who had a driving license and those who had not, and between the group of respondents from the north of Israel and a sample of participants from the center of the country. Lack of knowledge was revealed especially concerning knowledge about the BAC limit and youth vulnerability. Arabs tended to exaggerate the amount of drinks allowed to be consumed before driving according to the law, to hold common myths more than Jews and to get lower scores concerning alcohol main effects on driving skills. However, they tended to be more aware than Jews to youth vulnerability.     

Acceptance of drinking and driving and alcohol-involved driving crashes in California

BackgroundAlcohol-impaired driving accounts for substantial proportion of traffic-related fatalities in the U.S. Risk perceptions for drinking and driving have been associated with various measures of drinking and driving behavior. In an effort to understand how to intervene and to better understand how risk perceptions may be shaped, this study explored whether an objective environmental-level measure (proportion of alcohol-involved driving crashes in one’s residential city) were related to individual-level perceptions and behavior.MethodsUsing data from a 2012 cross-sectional roadside survey of 1147 weekend nighttime drivers in California, individual-level self-reported acceptance of drinking and driving and past-year drinking and driving were merged with traffic crash data using respondent ZIP codes. Population average logistic regression modeling was conducted for the odds of acceptance of drinking and driving and self-reported, past-year drinking and driving.ResultsA non-linear relationship between city-level alcohol-involved traffic crashes and individual-level acceptance of drinking and driving was found. Acceptance of drinking and driving did not mediate the relationship between the proportion of alcohol-involved traffic crashes and self-reported drinking and driving behavior. However, it was directly related to behavior among those most likely to drink outside the home.DiscussionThe present study surveys a particularly relevant population and is one of few drinking and driving studies to evaluate the relationship between an objective environmental-level crash risk measure and individual-level risk perceptions. In communities with both low and high proportions of alcohol-involved traffic crashes there was low acceptance of drinking and driving. This may mean that in communities with low proportions of crashes, citizens have less permissive norms around drinking and driving, whereas in communities with a high proportion of crashes, the incidence of these crashes may serve as an environmental cue which informs drinking and driving perceptions. Perceptual information on traffic safety can be used to identify places where people may be at greater risk for drinking and driving. Community-level traffic fatalities may be a salient cue for tailoring risk communication.     

“I drove after drinking alcohol” and other risky driving behaviours reported by young novice drivers

Background: Volitional risky driving behaviours such as drink- and drug-driving (i.e. substance-impaired driving) and speeding contribute to the overrepresentation of young novice drivers in road crash fatalities, and crash risk is greatest during the first year of independent driving in particular. Aims: To explore the: (1) self-reported compliance of drivers with road rules regarding substance-impaired driving and other risky driving behaviours (e.g., speeding, driving while tired), one year after progression from a Learner to a Provisional (intermediate) licence; and (2) interrelationships between substance-impaired driving and other risky driving behaviours (e.g., crashes, offences, and Police avoidance). Methods: Drivers (n = 1076; 319 males) aged 18–20 years were surveyed regarding their sociodemographics (age, gender) and self-reported driving behaviours including crashes, offences, Police avoidance, and driving intentions. Results: A relatively small proportion of participants reported driving after taking drugs (6.3% of males, 1.3% of females) and drinking alcohol (18.5% of males, 11.8% of females). In comparison, a considerable proportion of participants reported at least occasionally exceeding speed limits (86.7% of novices), and risky behaviours like driving when tired (83.6% of novices). Substance-impaired driving was associated with avoiding Police, speeding, risky driving intentions, and self-reported crashes and offences. Forty-three percent of respondents who drove after taking drugs also reported alcohol-impaired driving. Discussion and Conclusions: Behaviours of concern include drink driving, speeding, novice driving errors such as misjudging the speed of oncoming vehicles, violations of graduated driver licensing passenger restrictions, driving tired, driving faster if in a bad mood, and active punishment avoidance. Given the interrelationships between the risky driving behaviours, a deeper understanding of influential factors is required to inform targeted and general countermeasure implementation and evaluation during this critical driving period. Notwithstanding this, a combination of enforcement, education, and engineering efforts appear necessary to improve the road safety of the young novice driver, and for the drink-driving young novice driver in particular.     

Young driver crash rates by licensing age,driving experience,and license phase

Background

Few studies have concurrently assessed the influence of age and experience on young driver crashes, in particular in the post-Graduated Driver Licensing (GDL) era. Further, little attention is given to the transition from intermediate to full licensure. We examined the independent and joint contributions of licensing age, driving experience, and GDL license phase on crash rates among the population of young New Jersey (NJ) drivers.

Methods

From a unique linked database containing licensing and crash data, we selected all drivers who obtained their NJ intermediate license at 17–20 years old from 2006–2009 (n = 410,230). We determined the exact age at which each driver obtained an intermediate and full license and created distinct, fixed cohorts of drivers based on their age at intermediate licensure. For each cohort, we calculated and graphed observed monthly crash rates over the first 24 months of licensure. Further, we examined crash rates by age at licensure, driving experience (i.e., time since licensure), and license phase.

Results

First-month crash rates were higher among the youngest drivers (licensed at 17y0m). Drivers who were licensed later experienced a reduced “steepness” in the slope of their crash rates in the critical initial months of driving, but there did not appear to be any incremental benefit of later licensure once drivers had six months of driving experience. Further, at each age, those with more driving experience had lower crash rates; however, the benefit of increased experience was greatest for the substantial proportion of teens licensed immediately after becoming eligible (at 17y0m). Finally, independent of age and experience, teen drivers’ crash risk increased substantially at the point of transition to a full license, while drivers of a similar age who remained in the intermediate phase continued to experience a decline in crash rates.

Conclusion

Age and driving experience interact to influence crash rates. Further, independent of these two factors, there is an abrupt increase in crash risk at the point of transition from intermediate to full licensure. Future studies should investigate whether this increase is accounted for by a change in driving exposure, driving behaviors, and/or other factors.     

Identifying factors that increase the likelihood of driving after drinking among college students

Driving after drinking (DAD) is a serious public health concern found to be more common among college students than those of other age groups or same-aged non-college peers. The current study examined potential predictors of DAD among a dual-site sample of 3753 (65% female, 58% Caucasian) college students. Results showed that 19.1% of respondents had driven after 3 or more drinks and 8.6% had driven after 5 or more drinks in the past 3 months. A logistic regression model showed that male status, fraternity or sorority affiliation, family history of alcohol abuse, medium or heavy drinking (as compared to light drinking), more approving self-attitudes toward DAD, and alcohol expectancies for sexual enhancement and risk/aggression were independently associated with driving after drinking over and above covariates. These results extend the current understanding of this high risk drinking behavior in collegiate populations and provide implications for preventive strategies. Findings indicate that in addition to targeting at-risk subgroups, valuable directions for DAD-related interventions may include focusing on lowering both self-approval of DAD and alcohol-related expectancies, particularly those associated with risk/aggression and sexuality.     

Prevalence of impaired driving behaviors in a diverse, rural, southern middle school

Little research has been reported on the risky behaviors of pre-driving adolescents revolving around alcohol use, in particular impaired driving behaviors, which in general have been shown to be higher in rural areas. This study investigated the prevalence of drinking while driving and riding with a drinking driver among 290 middle school students in a Mississippi Delta area middle school. Just under half (45.3%) responded that at least once in the past 30 days they had ridden with a drinking driver and 17% indicated they had driven an automobile after drinking alcohol. The prevalence of underage drinking, driving under the influence of alcohol, and riding with a drinking driver among our sample of middle school students is alarming. This study shows alcohol-related driving behaviors are not solely performed by those who are legally licensed to drive, but simply by those who have access to vehicles. The authors recommend that prevention programs focusing on reducing the incidence of impaired driving should start in early adolescence.     

A population-based study on the prevalence and correlates of drinking and driving in Hong Kong

To examine the prevalence and correlates of drinking and driving in Hong Kong, an anonymous, random telephone survey was conducted on 9860 Chinese adults (18-70 years of age) from April to June 2006. Trained interviewers administered a structured interview consisting of questions on socio-demographic information, drinking pattern, drink-driving, and motor vehicle accidents. The census age-standardized past-year prevalence of driving within 2 h of drinking was 5.2% among males and 0.8% among females. The prevalence across age showed an inverted U-shaped trend for males peaking at 8.2% between 41 and 45 years. For females the prevalence was fairly stable between the ages of 20 and 55. The past-year prevalence of alcohol-related motor vehicle accidents was 0.1%, with the majority being in the 26-30 age group. For males who drank, the prevalence of drinking and driving was 5.0% among those without problem drinking, 14.8% among binge drinkers, 37.1% among alcohol abusers and 22.4% among the alcohol dependent. For females who drank, the corresponding figures were all lower at 1.2%, 6.9%, 12.1% and 12.5%, respectively. Higher socio-economic status, weekly drinking, binge drinking and alcohol abuse were independently associated with higher likelihood of drinking and driving in both genders. Among drinking drivers, having a job that required drinking was the only predictor of having had a motor vehicle accident. The elevated prevalence of drinking and driving among alcohol abusers, binge drinkers and the alcohol dependent may portend higher population-level rates of alcohol-related motor accidents in the future since the prevalence of problem drinking has previously been noted to be increasing rapidly in Hong Kong.     

The relationship of underage drinking laws to reductions in drinking drivers in fatal crashes in the United States

This study reports on an effort to evaluate and interrelate the existence and strength of two core laws and 14 expanded laws designed to (a) control the sales of alcohol, (b) prevent possession and consumption of alcohol, and (c) prevent alcohol impaired driving by youth aged 20 and younger. Our first analysis determined if the enactment of the possession and purchase laws (the two core minimum legal drinking age laws) was associated with a reduction in the ratio of drinking to nondrinking drivers aged 20 and younger who were involved in fatal crashes controlling for as many variables as possible. The ANOVA results suggest that in the presence of numerous covariates, the possession and purchase laws account for an 11.2% (p=0.041) reduction in the ratio measure. Our second analysis determined whether the existence and strength of any of the 16 underage drinking laws was associated with a reduction in the percentage of drivers aged 20 and younger involved in fatal crashes who were drinking. In the regression analyses, making it illegal to use a false identification to purchase alcohol was significant. From state to state, a unit difference (increase) in the strength of the False ID Use law was associated with a 7.3% smaller outcome measure (p=0.034).     

Impaired driving and motor vehicle crashes among Swedish youth: an investigation into drivers' sociodemographic characteristics

Impaired driving is an important road safety problem, and the characteristics of drivers impaired by alcohol or drugs are relevant to targeted interventions. This study considers young drivers' sociodemographic attributes: age, sex, class of origin and educational attainment, based on a national cohort of young Swedish drivers (1988-2000) followed up in police registers for their first motor vehicle crash. Of all crashes reported for these drivers, 946 were where the driver was suspected of being under the influence of alcohol or other substances (corresponding to 6% of all first crashes). Impaired driving significantly increases the odds of severe and fatal injuries, regardless of sociodemographic attributes. Observed differences in the proportions of impaired drivers reveal significant excess risks among males, persons aged 18-19, those from households classified as "workers" and "others" (including, e.g. the long-term unemployed and those on long-term sick leave), and those with low educational attainment. Impaired driving is a risk factor in all sociodemographic strata among young people. Members of some groups are more likely to be found than others among impaired drivers on occasion of first motor vehicle crash.     

The effect of the new traffic law on drinking and driving in São Paulo,Brazil

Objective

To present data on drinking and driving in the city of São Paulo, Brazil, and the effects of the new traffic law (Law 11,705) introduced in 2008.

Methods

A cross-sectional study was performed using a questionnaire and passive breath test data to study the prevalence of drinking and driving and the association of drinking and driving with background characteristics and drinking patterns on two separate occasions. The data were gathered from 2007 to 2009 through roadside surveys conducted on busy public roads. Four thousand two-hundred thirty-four (4234) drivers were approached, before and after prohibition, from the south, north, east, and west regions of the city of São Paulo, located in southeastern Brazil, including cars, motorcycles, and utility vehicles. A total of 3854 (91%) consented to participate in the survey and answered the questionnaire. Out of this group, 3229 (84%) agreed to take the passive breathalyzer test.

Results

Logistic regression analyses controlling for gender and age was used to predict a positive breath test (above 0.2 g/l) and the impact of the new law. These analyses indicated that, after the passage of the new traffic law, there was a 45% decrease in driver behavior with positive breathalyzer results. Having a pattern of alcohol consumption of at least once a week and the habit of drinking and driving are risks for a positive breathalyzer.

Conclusions

Despite the decline in the frequency of motorists driving under the influence of alcohol, traffic-related injuries and deaths, after the new law, other measures for a public policy related to alcohol should be considered based on scientific evidence, consistency of action, clear goals, community support, and greater reliability in the laws.