INTRODUCTION

This is the final report of a project entitled "Alcohol Highway Safety Problem Update." The project was conducted by Mid-America Research Institute, Inc., of New England for the National Highway Traffic Safety Administration (NHTSA) under contract number DTNH22-93-C-05083.

The work reported here critically examines new literature and data on selected alcohol-crash targets or problems that have become available since the last NHTSA sponsored State of Knowledge review published in November, 1989 (Jones and Lacey, 1989). Specifically, this update addresses research since the 1989 review dealing with characteristics of drinking-drivers and drinking-driving that are associated with increased levels of alcohol-crash risk and/or alcohol-crash incidence. Broad categories of topics covered by this research are:

People at risk

BAC (blood alcohol concentration) levels at risk

Environmental situations at risk

The materials reviewed here are those dealing with the epidemiology of the alcohol-crash problem created by various groups of drivers in various drinking and driving situations. The materials included foreign as well as U.S. literature with a direct bearing on highway safety. The intent of the review was to identify high-risk groups or situations which might be amenable to countermeasures so that appropriate countermeasures could be developed and tested in further research activities. With the exception of NHTSA's Traffic Safety Facts 1996, the cutoff date for literature included in this study was February, 1994.

STUDY APPROACH

Potentially relevant documents were identified through an extensive search of the literature with input from researchers and practitioners in the field of alcohol and highway safety. The principal investigators used two primary criteria for screening substantive materials for subsequent review. First, a document actually had to address pertinent topics. Second, a document had to at least purport to have scientific validity. Documents merely reflecting the unsupported opinions of their author were not retained for review. Documents surviving this initial screening underwent further screening to determine whether they really did have scientific validity and whether the treatment of the results was objective and balanced.

The reviews of each document followed a common format, each review taking into account the major issue or issues addressed by the research and identifying any trends that may have been suggested by the research when considered in the light of prior research or prior trends. Major topics addressed in the individual reviews were:

The research method followed;

Quality of the data;

Sample sizes and statistical significance of the results;

Actual amount of differences among groups that may be compared in a study;

Appropriateness of the techniques used to analyze the data; and

Appropriateness of the findings and conclusions in light of the actual results reported.

After preparing the individual reviews, we developed a synthesis of the materials along with our own conclusions about the findings of the literature.

FINDINGS AND CONCLUSIONS

The identification of targets for alcohol-crash countermeasures requires information about the number of alcohol-related crashes, the extent of alcohol-impaired driving, and the relative risk of an alcohol-related crash. The literature examined in this update relates almost entirely to the first two of these areas, adding useful information about:

This is the final report of a project entitled "Alcohol Highway Safety Problem Update." The project was conducted by Mid-America Research Institute, Inc., of New England for the National Highway Traffic Safety Administration (NHTSA) under contract number DTNH22-93-C-05083.

Nearly 30 years have passed since the first comprehensive review of the state of knowledge about alcohol and highway safety conducted by the U.S. Department of Transportation (1968). NHTSA has sponsored three updates of the landmark 1968 study, the first published in 1978 (Jones and Joscelyn, 1978), the second in 1984 (U.S. Department of Transportation, 1985), and the third in 1989 (Jones and Lacey, 1989). The 1978 update was actually a complete revision, both in form and content. It re-examined the literature used in the prior review, added new material published since 1968, and developed a new structure for integrating and synthesizing the material.

The 1985 update had more modest objectives. Called an "interim update" by its author, it included the "most clearly important studies and findings from the period from January 1978 to December 1982," and left "large portions of the original . . . intact." The 1985 update included the citations from the 1978 report in a separate section from the citations used in the 1985 report. Together, the two reports contain some 500 citations.

The most recent review (Jones and Lacey, 1989) again covered the complete spectrum of alcohol-crash issues but was limited in its treatment of those issues to identify trends and new developments since the 1985 update. Over 2,000 documents were examined in the 1989 review, 756 of which were retained as references.

The materials reviewed here are those dealing with the epidemiology of the alcohol-crash problem created by various groups of drivers in various drinking and driving situations. The scope of the review included foreign as well as U.S. literature with a direct bearing on highway safety. As indicated in Chapter 1, broad categories of topics covered were:

People at risk

BAC levels at risk

Environmental situations at risk

Mid-America obtained input from specialists that could be used to more clearly define the components of these broad categories. Input included detailed topics and issues; criteria for identifying target groups; and definitions of target groups. We also contacted professional committees and societies whose members contribute to the pertinent scientific literature. Two such committees were particularly important:

The Transportation Research Board Committee on Alcohol, Other Drugs, and Transportation; and

The National Safety Council Committee on Alcohol, Drugs, and Traffic Safety.

Input was also obtained from members of public action groups such as Mothers Against Drunk Driving (MADD) and from industry-sponsored associations such as the Insurance Institute for Highway Safety. We also obtained input from NHTSA and from contractor staff not directly involved in the project.

These individuals and organizations were contacted by letter and by personal telephone calls, as appropriate, early in the project. We also asked for input on pertinent literature as well as topics and issues.

The library of The University of Michigan Transportation Research Institute (UMRTI) was the central focus and coordinating element of the literature search and collection activities. This facility now has a collection of some 80,000 documents relating to highway safety, not including some 40,000 on microfiche. It has recently been computerized, permitting rapid and effective searches by keyword. Further, it has access to other computerized information services (such as TRIS/HRIS) through DIALOG and other time-sharing systems.

The starting point in the search was recent bibliographies and reviews of directly related materials. Relevant bibliographies and reviews were identified through a search of the UMTRI library, and through discussions with subject-matter experts and others as indicated above. The publications Alcohol, Drugs and Traffic Safety, Current Research Literature; Alcohol, Drugs and Driving: Abstracts and Reviews; and Addiction Research Foundation Library Acquisitions List were particularly useful at this point in the project.

We also obtained input from our colleagues on pertinent collections and individual documents covering the entire range of subjects to be addressed in the update. We were particularly interested in obtaining cites to literature that may not routinely be acquired by specialized highway-safety libraries. We also were interested in identifying important work in progress. Other research in progress was identified by contacting likely sponsors of research, most particularly, the National Institute on Alcohol Abuse and Alcoholism (NIAAA). The ICADTS Reporter (International Council on Alcohol, Drugs and Traffic Safety) and the UMTRI Research Review (University of Michigan Transportation Research Institute) also contained information on research in progress.

The next step in the search was to methodically examine specific journals and conference proceedings known by the principal investigators to contain pertinent materials. These documents were not necessarily concerned directly with highway safety, but tended to focus on other related disciplines such as human factors, toxicology, issues concerning "special populations," and alcohol studies in general. Particularly important examples of journals in this group of publications were:

Accident Analysis and Prevention;

American Journal of Public Health;

Alcohol and Health Research World;

Blutalkohol;

British Journal of Addiction;

Human Factors;

Journal of Criminal Justice;

Journal of Forensic Sciences;

Journal of Hispanic Studies

Journal of Safety Research;

Journal of Studies on Alcohol;

Journal of Traffic Medicine;

Law and Policy; and

Psychopharmacologia.

Examples of ongoing conferences generating proceedings of interest were:

The triennial international conferences on Alcohol, Drugs and Traffic Safety; and

The annual conferences of the Association for Advancement of Automotive Medicine.

The documents that were identified through the above process were potentially relevant, but they could not actually be selected for review until they were read and screened by the principal investigators.

There were two primary screening criteria for substantive materials. First, a document actually had to address pertinent topics as it appeared to when it was identified as a candidate. Second, a document had to at least purport to have scientific validity. Documents merely reflecting the unsupported opinions of their author were not retained for review.

Documents surviving this initial screening underwent further screening to determine whether they really did have scientific validity, that is, whether the methods used in designing and executing the research, and in analyzing the results were sound. Further, they were examined to determine whether the treatment of the results was objective and balanced. However, documents that were believed to be flawed in some respect were not necessarily rejected in this screening. For example, a study that was well-designed and executed, but drew conclusions that did not flow from its findings was kept for the update. The update's commentary on that study noted the inconsistencies between the research results and the conclusions, and offered a more consistent interpretation of the results.

As in prior state of knowledge reviews, each document identified for inclusion in the alcohol update report was critically reviewed by the authors. However, these individual reviews were formalized in this project to follow a common format for incorporation. Each review took into account the major issue or issues addressed by the research and identified any trends that may have been suggested by the research when considered in the light of prior research or prior trends. Major elements of the reviews were:

the research method followed;

quality of the data;

sample sizes and statistical significance () of the results (findings with greater than the usual 0.05 were not necessarily disregarded);

effect size: actual amount of differences among groups that may be compared in a study (e.g., 85% of group 1 vs. 80% of group 2 has a small effect size);

appropriateness of the techniques used to analyze the data; and

appropriateness of the findings and conclusions in light of the actual results reported.

As indicated earlier in this chapter, if the reviewers believed the conclusions of a study were inappropriate, the inconsistencies between the research results and the conclusions were noted, and a more consistent interpretation of the results was offered.

Bibliographic information on each article was entered into a computerized bibliographic database. Finally, the last step in conducting the update was the preparation of this report synthesizing he reviews.

This review was performed to identify information that could be used for better defining alcohol-crash target groups or problems so that new or improved countermeasures could be developed. This chapter contains a synthesis of the individual reviews. The discussion is in three sections, (1) some general comments on the general nature of the literature, (2) the synthesis of literature findings, and (3) a summation of the findings and the authors' general conclusions about those findings. This section deals with the literature from the perspective of BACs at risk, people at risk, and environmental situations at risk.

GENERAL NATURE OF THE LITERATURE

The articles identified in our literature search and reviewed in this report fall into three major categories, as follows:

1. Those that examine the alcohol-crash incidence or risk of various subgroups of drivers;

2. Those that examine the characteristics of various subgroups of drinking-drivers and drinking-driving situations; and

3. Those that set out explicitly to identify target groups of drinking-drivers.

The first category deals primarily with subgroups that can be defined from variables in the archival crash data sets and driver data sets that are available to traffic safety researchers, and from variables in special data sets that have been developed from roadside surveys of non-crash involved drivers. This type of study is called an epidemiologic study in the traffic safety literature. We note that no epidemiologic study was found that developed both the crash data and the non-crash data that were used in the study.

The second category deals with data on subgroups of drivers that have already been identified as engaging in drinking-driving. Examples of such subgroups are drivers who have been arrested for DWI and drivers who have been convicted of DWI and required by the court to attend treatment or educational sessions. Sometimes, surveys of drivers or subgroups of drivers (for example, young drivers) are used to identify, through self-reports, drinking drivers who may then be compared with non-drinking drivers to identify characteristics that differentiate the drinking drivers and the non-drinking drivers. Very often, additional data are gathered on the drivers studied, including data resulting from administering various psychological scales and from instruments designed to measure alcohol abuse or dependence.

Articles in the second category far outnumbered those in the other two categories. Only a few articles fell in the third category, some based on primary data and others on secondary data, including literature reviews and interpretations of literature reviews.

As might be expected, the research method and data used in the documents reviewed here varied according to the type of study or report. Some documents, such as the 1997 report from NHTSA's Fatality Analysis Reporting System (FARS), were simply a straight presentation of data on a drinking-driving group, with no comparison to any other drinking-driving group. At the opposite end of the spectrum were studies that attempted to follow an experimental or quasi-experimental design, with random assignment to treatment and control groups. Because of self-selection of subjects or other factors that could not be controlled by the investigators, very few studies achieved such a design and accounted analytically for differences between treatment and control groups, if at all.

More common were studies that used a study population and study sample of convenience, often in some location nearby the offices of the investigators. The few studies that were based on national data or on a sample chosen to represent the nation as a whole used data from FARS or from the National Roadside Breathtesting Surveys of 1973 and 1986. Clearly, generalizing the results of a localized study to the nation as a whole is not warranted, a fact that severely limits the usefulness of most of the individual studies reviewed in this report in developing national policies and strategies. However, many of these studies are useful for this purpose when examined in the light of other studies, providing information that can be pieced together with other information to suggest or support a hypothesis or line of inquiry. This situation is, of course, not unique to the field of traffic safety, occurring commonly in just about all of the sciences and especially in the field of epidemiology.

Another type of study that appeared rather frequently in the literature was an examination of the attributes of some high-risk drinking-driving group (usually DWIs) to identify factors that were associated with just that group. Usually, this type of study used no control or comparison group of non-DWIs, but was simply concerned with the attributes of the chosen high-risk group. Still other, more sophisticated studies used multiple comparison groups, sometimes drawing their subjects for one group from one source (for example, DWIs in a treatment program) and its subjects for another group from another source (for example, a survey of the general driving population).

The sample sizes used in the research reviewed in this report varied from the entire population of U.S. drivers in fatal crashes to less than 100 drivers who had been injured in traffic crashes in some city or county. The studies based on the smaller sample sizes often appeared adequate from the standpoint of sample size for detecting meaningful general effects at a reasonable level of significance. The comments on statistical power of the tests the investigators used in their analyses are based on the reviewers' experience with similar research, since none of the studies explicitly identified the power of their tests.

Most of the studies that performed statistical tests reported the level of significance determined by the test, even when the result was below the 0.05 level. However, very few of the studies reporting the statistical significance of their findings discussed the practical significance of their findings, for example, whether a statistically significant difference of 0.04 in the mean scores of two groups on a psychometric test scale with a range of 0 to 1 has any practical significance in classifying the subjects in the two groups.

For the most part, the investigators were candid and objective about their findings, offering appropriate caveats. However, there were some glaring exceptions, including the finding of one study with a sample size of 58 about adequacy of the U.S. legal system in dealing with the drinking-driving problem.

FINDINGS OF THE LITERATURE

BACs at Risk

People at Risk

Biographical Variables. Several recent studies have examined the effect of various biographical variables on alcohol-crash risk. Findings with respect to each of these variables are summarized below.

Driver Age

Prior state of knowledge updates have found that very young drivers and very old drivers were found to drink and drive less frequently, but the very young drivers had a much greater alcohol-crash risk when they did drive. The 1984 update presented data from NHTSA's Fatal Accident Reporting System (subsequently renamed the Fatality Analysis Reporting System or FARS) providing additional confirmation that the youngest drivers tend to have the highest risk of an alcohol-related fatal crash, on the order of 4.5 per 100 million vehicle miles traveled for teen-age drivers, compared to about 1.5 for drivers aged 25-44. Younger drivers were found to be on the road more often during late nighttime hours and on weekends than were older drivers. The 1989 study reported that the most important development since the 1984 update was that the percentage of crashes involving alcohol had declined during the 1980s, and that the share of young drivers in alcohol-related crashes has been disproportionately reduced.

The analysis by Connolly, Kimball, and Moulton (1989) mentioned above suggests that female drivers have both a higher overall crash risk and a higher alcohol-related fatal-crash risk. Combined data from FARS and the 1986 National Roadside Breathtesting Survey suggest that the relative fatal-crash risk of a female driver with a BAC of 0.10% or more could be of the order of 50% higher than it is for a male driver at the same BAC. Of course, estimates based on these two unmatched data sets are, as indicated above, are only very rough, but they are consistent with prior case-control studies (see Jones and Joscelyn 1978).

Donovan et al. (1990) examined the driver records of a 1% sample of all licensed drivers in the State of Washington in 1979. They found that, overall, 2.1% of these 39,011 drivers were arrested for DWI during a three-year follow-up period. However, these rates were quite different for male and female drivers, the rate for males being 3.4% compared to only 0.7% for females.

Wells-Parker and associates (1991) found a number of differences and similarities between male and female DWIs referred by the courts in 11 Mississippi jurisdictions to a follow-up project that may be useful in identifying specific target groups for countermeasures. Female DWIs were more likely to be older, Caucasian, divorced, and unmarried, and to have no prior DWI offenses and fewer arrests for public drunkenness offenses. Further, females were only half as likely as males to recidivate in the two years following their conviction. Females and males did not differ with respect to BAC at time of arrest, nor with respect to the distribution of their Mortimer-Filkins scores. Meyers et al. found that males were significantly more likely to be multiple offenders than females (Transportation Research Board 1993).

Shore and associates (1988) gave the characteristics of female DWIs in Wichita, Kansas, but, for the most part, did not compare them with those of male DWIs. These researchers did note, however, that the distribution of arrests by day of the week did differ significantly for males and females, with females tending to be arrested less frequently during the weekend.

Driver Race

The role of race in the alcohol-crash problem has rarely been addressed in prior research. The 1978 update found some suggestion of a race effect, but could not separate the effect of race from the effect of socio-economic status. The 1989 update reported that data from the first report on the 1986 National Roadside Breathtesting Survey showed that the percentage of white drivers with a BAC of 0.10%+ was about half what it was in 1973, but the percentage of black drivers at these BACs had remained essentially unchanged. The most recent report on the 1986 survey (Lund and Wolfe 1991) found that 5.9% of blacks had a BAC of 0.10% or more compared to 2.7% for whites (p=0.03). Hispanics were also over-represented compared to whites (4.4%), but this difference was not significant because of the small number of Hispanics (124) in the sample and the small percentages involved. Further, the percentage of white drivers with a BAC of 0.10% or more declined nearly 90% from the 1973 roadside survey (5.1% to 2.7%), while the percentages of black drivers and Hispanic drivers with a BAC of 0.10% or more stayed about the same.

Popkin and Council (1993) examined crash data in North Carolina to determine the role of white and non-white drivers. Their findings on fatally injured drivers are of particular interest, since BACs were available. Their data indicate that 51% of non-white drivers and 49% of white drivers had a BAC of 0.10% or more, but this difference is not statistically significant (p=0.30).

However, there were significant differences in North Carolina with respect to race for various age and sex subgroups of drivers. For example, 58% of male non-white drivers had a BAC of 0.10% or more compared to 53% of male white drivers (p=0.009). The higher percentage of male non-white drivers was due to a much higher percentage with 0.10% or more in the over-24 years age group -- in the under-25 years age group, a higher percentage of white males had a BAC of 0.10% or more than did non-white males.

The picture was different for female non-white drivers, with only 23% having a BAC of 0.10% or more compared to 40% of female white drivers. The higher percentage for female white drivers was due to much higher percentages in the under-25 years age group and the over-54 years age group. White and non-white females in the 25-54 age group had about the same percentage of 0.10 drivers, 25% and 22%, respectively.

James (1990) examined the characteristics of non-white drivers who had been arrested for DWI in the State of Washington. He found that non-whites comprised 10.5% of the total DWI population. Among non-whites, 11% were Asian, 33% were African-American, 36% were Native American, and 20% were "unknown." His data indicate a small but significant (p=0.007) difference between whites and non-whites with respect to sex (15.7% of whites were female versus 13.8% of non-whites). With respect to age, James' data indicate highly significant (p=0.0000) differences between whites and non-whites, with the differences occurring in the under-30 (38% of non-whites versus 51% of whites) and 30-49 (53% of non-whites and 40% of whites) age groups.

James also compared the percentage of various ethnic groups in the DWI population with percentages in the general population and found that Asian-Americans were under-represented in the DWI population by a factor of about 3 to 1, blacks were over-represented by a factor of 1.25 to 1, and Native Americans were over-represented by a factor of 2.53 to 1. Data on Hispanics were not available in the James study, but Tashima and Helander (1993) found that Hispanics are substantially over-represented (38%) among DWI arrestees in California compared to their adult population representation (22%), a factor of 1.73 to 1. The degree to which any racial biases among the arresting officers may have influenced these figures is not known.

Using factor analysis, James identified five different profiles of non-white DWIs which he thought might be appropriate for the development of specially-targeted countermeasures:

Drinking Variables. Prior updates have presented considerable information on the effect of various drinking-related variables on alcohol-crash incidence and risk. They reported that beer is the preferred type of alcoholic beverage of drinking drivers by a large margin, especially among high-BAC drivers and by drivers reporting that they were heavy drinkers. Persons with severe drinking problems were found to be over-represented among fatally injured drivers with high BACs and among drivers who were judged responsible for the crashes in which they were killed.

We found no recent studies of the effect of drinking patterns on alcohol-crash risk, but several studies have examined various drinking-related variables for groups of drivers, and these studies expand the knowledge base in this area.

The 1986 National Roadside Breathtesting Survey (Lund and Wolfe 1991) presented data on the drinking habits and most recent alcohol beverage of drivers using the roads during weekend nighttime hours. The survey data indicate that 3.8% of the drivers who reported that they were very light or fairly light drinkers had a BAC of 0.10% or higher. However, 6.7% of drivers reporting that they were moderate to very heavy drinkers had a BAC of 0.10% or higher. Looked at another way, these data indicate that 35% of the 0.10% drivers were moderate to very heavy drinkers compared to only 22% of the drivers with a BAC of less than 0.10%. The survey data were consistent with earlier research indicating the preference of drivers for beer and wine over distilled spirits -- 78% of the 0.10% drivers and 69% of the other drivers preferred beer or wine over distilled spirits.

Data from the study by Vingilis et al. (1994) of drivers who had been seriously injured in traffic crashes in Ontario, Canada indicate that the drinking patterns of BAC-negative and BAC-positive differ along several dimensions that reflect heavy drinking. For example, 7% of the BAC-negative drivers and 15% of the BAC-positive drivers said that they had been intoxicated "many times" over the past 30 days. Similarly, 7% of the BAC-negative drivers and 14% of the BAC-positive drivers said that they drank every day over the past 30 days. Further, 4% of the BAC-negative drivers and 14% of the BAC-positive drivers reported a self-perceived drinking problem. On the other hand, the study by Wilson (1992) of various groups of Ontario drivers indicated that the crash-involved group (not necessarily "serious" crashes) had slightly more drinks per week and drinks per drinking occasion on the average than did the control group, but that the drinking frequency of the two groups was the same.

Recent studies continue to provide strong evidence of patterns of heavy drinking and alcohol abuse for DWIs as a group. For example, Nochajski, Miller, and Wieczorek (1992) found that a group of DWIs referred to an alcohol treatment program in western New York State had consumed five or more drinks per drinking occasion (a measure of "binge" drinking) on the average six to eight times in the past 30 days. Donovan et al. (1990) reported that a group of "high-risk" drivers who subsequently were arrested for DWI during a one-year follow-up period also had consumed five or more drinks per drinking occasion an average of 8.3 times in the past 30 days. By comparison, high-risk drivers who were not arrested for DWI during the same follow-up period had consumed five or more drinks per drinking occasion an average of 3.9 times in the past 30 days.

Another study by Wieczorek, Miller, and Nochajski (1992) applied criteria from the third edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III and DSM-IIIR) to the diagnosis of alcohol dependency of DWIs referred to a treatment program by the court. Their data indicate that, by these criteria, over 70% were alcohol abusers and that some 10% to 50% were alcohol-dependent. Data collected by Windle and Miller (1989) for a similar group of DWIs from the same area indicate that one-half of female subjects and two-thirds of male subjects had attended Alcohols Anonymous sessions. Further, about 6% of the females and 12% of the males in this group had been treated for alcohol abuse in the past.

Driving Variables. Prior updates have indicated that drinking-driving was primarily a nighttime phenomenon, with drinking drivers being found some two to four times as often in nighttime crashes as in daytime crashes. Day of the week was also found be a strong differentiator of drinking-driving, with more alcohol-related crashes and more drinking drivers found on the weekend than on weekdays. The origin of the trip which involved drinking-driving was most frequently bars or taverns and other persons' homes. The 1989 update reported that high-mileage drivers, drivers visiting friends, and drivers who were traveling for cultural or recreational purposes appeared to defy the general downward trend toward less involvement in higher-BAC driving, remaining about the same in this respect as they were in 1973.

Drinking-Driving Variables. Prior updates indicated that drinking drivers had slightly more previous crashes and substantially more enforcement actions (including DWI) against them than did other drivers. The only available recent U.S. data on the incidence of drinking-driving come from the 1986 National Roadside Breathtesting Survey (Lund and Wolfe 1991) of nighttime, weekend drivers. These data are discussed throughout this synthesis section as they apply to drivers with various characteristics.

There is also evidence that drivers with prior DWIs are more likely to be involved in severe traffic crashes than are other drivers. Data from FARS (Fell 1991) show that, in 1988, 3.3% of all licensed drivers had been arrested for DWI in the past three years, but 5.7% of all fatally injured drivers had been arrested for DWI in the past three years. This indicates that drivers with prior DWIs were over-represented in fatal crashes by a factor of about 1.8. Vingilis et al. (1994) found that their BAC-positive group of seriously injured drivers had five times the percentage of subjects who reported having driven at least once during the past month with a BAC of 0.08% or more than did the BAC-negative group (38% versus 7%).

The study by Donovan et al. (1990) which examined the driver records of 39,011 Washington State drivers illustrates the effect of having a prior arrest for DWI on the probability of a subsequent arrest for DWI. Nearly 20% of the drivers with priors were arrested again during a three-year follow-up period, compared to only 2.0% of the drivers with no priors. As indicated above, other variables also influence DWI arrest probability, including driver sex and driver age. In the study by Donovan and associates, males from the general driving population were five times as likely to be arrested for DWI during the follow-up period as were females. Further, 2.7% of drivers less than 30 years were arrested for DWI during this period compared with only 1.7% of drivers 30 years and older.

Personality and Psychosocial Variables. The 1978 update found evidence that several personality and stress variables were associated with drinking-driving, including alienation and hostility, belligerence, and negativism, but concluded that these findings were not conclusive or amenable to generalizing. The 1989 update found that subsequent research provided support for the hypothesis that drivers with a variety of behavioral problems are a factor in the drinking-driving problem, but did not provide a basis for estimating the relative importance of the role of such drivers in that problem.

A growing number of research studies are examining the influence of personality and psychosocial factors on the alcohol-crash problem, and some of these are directly related to the identification of target groups for DWI countermeasures. Several of these studies have been cited above. As we indicated in the 1989 update, the research designs involve a survey research approach, sometimes augmented by driver records data from state files. Usually, the questionnaires are self-reports, but they may also involve personal interviews and the use of psychometric scales. Sample sizes for the better studies range from a few hundred to several thousand. Populations surveyed include those of known high risk (for example, DWIs and drivers with multiple driving offenses or crashes in a recent time period), drivers in general, and special groups of drivers (for example, youthful drivers). Sophisticated multivariate statistical techniques are often used in analyzing the data. Much of this work has been done in Canada.

The findings from these two studies suggest that deviance from personality and psychosocial norms are associated with risky driving in general of which drinking-driving is just one component. However, such a generalization must be viewed with caution, because of the small sample sizes of these studies. The sample size used in the study by Donovan and associates was 254, with only 29 of these belonging to the group with a subsequent DWI. The study by Vingilis and associates had a sample size of 96, with only 22 of these belonging to the BAC-positive group.

Environmental Situations at Risk

Drinking Location. Prior updates suggested that the drinking location preceding illegal drinking-driving was most frequently bars or taverns and other person's homes. Several recent studies have examined drinking location as a correlate of drinking-driving. A study of New York State DWIs by Wieczorek, Miller, and Nochajski (1992) found that subjects who drank at more than one location engaged in DWI more often than did subjects who drank at only one location. The multiple-location DWIs had an average of 4.00 self-reported drunk driving events in the past 30 days compared to 2.46 for the single-location DWIs (p= 0.0009). In addition, the multi-location drinkers drove almost twice as far prior to their arrest (an average of 11.5 miles for multi-location versus 6.7 miles for single-location, p<0.0001 ), thereby exposing other drivers and their passengers to a greater crash risk. These two groups also differed significantly on a number of drinking variables, with the multi-location drinkers indicating patterns of heavier drinking and stronger evidence of alcohol problems and alcohol dependency.

A study of Vermont university students by Musty and Perrine (1990) found that some 70% of those under the legal drinking age reported drinking most frequently at private locations (for example, home, other person's homes, and clubs), and that about 75% of students above the legal drinking age reported drinking at public bars and restaurants.

Another study in Australia (Lang and Stockwell 1991) examined the effect of type of drinking location on crash involvement. This study involved subjects in Perth, Australia who had been arrested for DWI, either as a result of being involved in a crash (n=257) or having failed a roadside sobriety test (n=1,909). Two types of drinking locations were considered in the study, "unlicensed" locations (for example, private residences or public places such as parks) and "licensed" locations. The study found that the prior drinking location of the drivers whose DWI arrest occurred after a crash was more likely to be unlicensed than it was for drivers whose DWI arrest occurred after some other event or activity such as speeding or reckless driving (p=0.001). Thirteen percent of the drivers who drank in an unlicensed location were arrested after a crash compared to 8% of the drivers who drank in a licensed location. Note that these figures reflect the conditional probability of an arrest given a crash, not the unconditional probability of crash.

Target Group Studies

NHTSA's Tier 1 Task Force (U.S. Department of Transportation, NHTSA, Unpublished) described the initial efforts of a working group to identify appropriate target populations for NHTSA's Traffic Safety Programs. The approach employed a conceptual model that included four components: crash involvement, crash risk, contribution to the overall problem, and countermeasure effectiveness. Two expert panels, one from inside NHTSA and one from outside NHTSA, then examined existing data, concluding:

"This effort clearly revealed that existing national data bases will not provide the information we sought in order to better define high-priority target populations in terms of social, economic, demographic and behavioral characteristics."

Nevertheless, the panels eventually developed a synthesis that pointed toward two categories of alcohol-crash target groups:

1. High-risk target populations with high impact on national alcohol-related crash rates; and

2. High-risk target populations with low impact on national alcohol-related crash rates.

Priority targets in the first group were: young beginning drivers 15-25 years old, male; drivers with repeated moving violations, especially alcohol-related; drivers with risky lifestyles; and nonusers of seatbelts. Priority targets in the second group were: Hispanics, especially 21-35 year old males; probably of lower socioeconomic status; Blacks, especially 30-40 year old males of low socioeconomic status; Native Americans of low socioeconomic status in rural areas; and male motorcyclists of all age groups.

SUMMARY AND CONCLUSIONS

The identification of targets for alcohol-crash countermeasures requires information about the number of alcohol-related crashes, the extent of alcohol-impaired driving, and the relative risk of an alcohol-related crash. The literature examined in this update relates almost entirely to the first two of these areas, adding useful information about:

GLOSSARY

ADS Alcohol Dependance Scale. Twenty-five item scale developed by the Addiction Research Foundation.

BAC Blood or breath alcohol concentration. The usual ratio standards are the number of grams of alcohol either per 100 milliliters of blood, or per 210 liters of breath.

BAL Blood alcohol level. The usual ratio standards are the number of grams of alcohol either per 100 milliliters of blood, or per 210 liters of breath.

BrAC Breath alcohol concentration. The usual ratio standards are the number of grams of alcohol per 210 liters of breath.

DIS Diagnostic Interview Schedule.

DSMIII American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, a multiple criteria-based diagnostic system.

DSMIIIR A structured clinical interview devised by Spitzer and Williams to diagnose mental disorders, including substance abuse disorders, as directed by revised diagnostic criteria of the American Psychiatric Association.

DUI Driving under the influence. General term used to describe the criminal action of operating a vehicle while under the influence of alcohol or other drugs.

DWI Driving while intoxicated, or driving while impaired. General term used to describe the criminal action of operating a vehicle while intoxicated, impaired or under the influence of alcohol or other drugs.

FARS Fatality Analysis Reporting System. (Formerly Fatal Accident Reporting System.) A NHTSA system which has collected information on fatal crashes since 1975 in all states, including data on alcohol involvement.

GES The National Highway Traffic Safety Administration's General Estimates System, which uses data from many sources including police reported crashes and the National Automobile (formerly Accident) sampling system to generate national estimates of all types of crashes including all types of vehicles.

GGT Blood levels of Gammaglutamyltransferase. The enzyme has been found to be a relatively sensitive index of liver damage in clinical studies of alcoholics and heavy drinkers.

MAST Michigan Alcohol Screening Test. A 10-15 minute, 24 item (Yes/No) test; self or counselor administrated resulting in one of three categories: no drinking problem, possible problem, alcoholism.

MORTIMER-FILKINS A 45-90 minute, 58 item (True/False, Yes/No, and

short answer) questionnaire plus a structured interview resulting in one of three categories: social drinker, presumptive problem drinker, problem drinker. Specifically designed for court assessment of DWI/DUI offenders.

N or n Mathematical term denoting sample size.

NIAAA National Institute on Alcohol Abuse and Alcoholism. One of 17 institutes that comprise the National Institutes of Health. NIAAA supports and conducts biomedical and behavioral research on the causes, consequences, treatment, and prevention of alcoholism and alcohol-related problems.

REVIEWED ARTICLES

Adebayo, A. (1991). Factors antecedent to impaired driving in a Canadian urban sample. International Journal of the Addictions 26(8):897-909.

Arnett, J. (1990). Drunk driving, sensation seeking, and egocentrism among adolescents. Personality and Individual Differences 11(6):541-546.

Connolly, MA; Kimball, AW; and Moulton, LH. (1989). Alcohol and traffic safety: a sensitivity analysis of data from composite sources. Accident Analysis and Prevention 21(1):1-31.

DiBlasio, FA. (1988). Predriving riders and drinking drivers. Journal of Studies on Alcohol 49(1):11-15. (January 1988).

Donovan, DM; Umlauf, RL; and Salzberg, PM. (1990). Bad drivers: identification of a target group for alcohol-related prevention and early intervention. Journal of Studies on Alcohol 51(2):136-141.

Donovan, JE. (1993). Young adult drinking-driving - behavioral and psychosocial correlates. Journal of Studies on Alcohol 54(5):600-613.

Everest, JT; Banks, S; Hewer, PA; and Mineiro, J. (1991). Drinking behaviour and breath alcohol concentrations of road accident casualties. Crowthorne, England: Transport and Road Research Laboratory, Oxford Road Accident Group, Oxford University.

Fell, JC. (1991). Repeat DWI offenders: their involvement in fatal crashes. In: Intoxicated Drivers: Multiple and Problem Offenders' Conference. Stevens Point, WI, 5-6 September, 1991. Washington, D.C.: National Highway Traffic Safety Administration, Office of Alcohol and State Programs.

Fontaine, RA. (1992). DUI pre-arrest alcohol purchases: a survey of Sonoma County drunk drivers. Journal of Studies on Alcohol 53(4):345-348. (July 1992).

Gould, LA; and Gould, KH. (1992). First-time and multiple-DWI offenders: a comparison of criminal history records and BAC levels. Journal of Criminal Justice 20(6):527-539.

Gruenewald, PJ; Stewart, K; and Klitzner, M. (1990). Alcohol use and the appearance of alcohol problems among first offender drunk drivers. British Journal of Addiction 85(1):107-117.

Hayes, DM; and Swisher, JD. (1991). Social activity participation and the drinking and driving behaviors of adolescents. Journal of Alcohol and Drug Education 36(3):7-16.

James, WH. (1990). A report on driving while intoxicated (DWI) among Asian-Americans, African-Americans, Hispanic-Americans, and Native Americans for the Washington traffic safety commission. Seattle, Washington: Center for the Study and Teaching of At-Risk Students, University of Washington.

Jones, RK; Joksch, HC; and Wiliszowski, CH. (1991). Implied consent refusal impact. Final report. Washington, DC: National Highway Traffic Safety Administration.

Klepp, KI; Perry, CL; and Jacobs, DR. (1991). Etiology of drinking and driving among adolescents: Implications for primary prevention. Health Education Quarterly 18(4):415-427.

Knight, KK; Fielding, JE; and Goetzel, RA. (1991). Correlates of motor-vehicle safety behaviors in working populations. Journal of Occupational Medicine 33(6): 705-710.

Lang, E; and Stockwell, T. (1991). Drinking locations of drink-drivers: a comparative analysis of accident and nonaccident cases. Accident Analysis and Prevention 23(6):573-584.

Lauber, JD; and Kayten, PJ. (1989). Fatigue, alcohol and drug involvement in transportation system accidents. Alcohol, Drugs and Driving 5(3):173-184.

Lewis, CC. (1988). Preventing traffic casualties among youth: What is our knowledge base? Alcohol, Drugs and Driving 4(1):1-8.

Lucker, GW; Kruzich, DJ; Holt, MT; and Gold, JD. (1991). The prevalence of antisocial behavior among U.S. Army DWI offenders. Journal of Studies on Alcohol 52(4):318-320.

Lund, AK; and Wolfe, AC. (1991). Changes in the incidence of alcohol-impaired driving in the United States, 1973-1986. Journal of Studies on Alcohol 52(4):293-301.

Martens, CH; Ross, LE; and Mundt, JC. (1991). Young drivers' evaluation of driving impairment due to alcohol. Accident Analysis and Prevention 23(1):67-76.

Mookherjee, HN. (1988). Some social characteristics of drinking drivers in rural Tennessee. Journal of Alcohol and Drug Education 34(1):64-70.

Mounce, NH; and Pendleton, OJ. (1992). The relationship between blood alcohol concentration and crash responsibility for fatally injured drivers. Accident Analysis and Prevention 24(2):201-210.

Musty, RE; and Perrine, MW. (1990). Driving, drinking and drug use: students and the 21-year-old drinking age. In: Proceedings of the 11th ICADTS Conference, T89, National Safety Council. Chicago, IL, 1990. pp 500-506.

Nelson, D; Sklar, D; Skipper, B; and McFeeley, PJ. (1992). Motorcycle fatalities in New Mexico: the association of helmet nonuse with alcohol intoxication. Annals of Emergency Medicine 21(3):279-283.

Nochajski, TH; Miller, BA; Wieczorek, WF; and Whitney, R. (1993). The effects of a drinker-driver treatment program. Does criminal history make a difference? Criminal Justice and Behavior 20(2):174-189.

Nochajski, TH; Miller, BA; and Wieczorek, WF. (1992). The New York state drinking-driver program screening project. In: Drinking, Drugs and Driving. Research note 92-2. Albany, New York: Office of Alcoholism and Substance Abuse Services.

Noordzij, PC; Vis, AA; and Verschuur, WL. (1990). Alcohol and the use of seat belts. In: Proceedings of the 11th ICADTS Conference, T89, National Safety Council. Chicago, IL, 1990. pp 677-683.

Olkkonen, S. (1993). Health disorders, alcohol and ageing in fatal bicycle injuries. Journal of Traffic Medicine 21(1):29-37.

Popkin, CL. (1991). Drinking and driving by young females. Accident Analysis and Prevention 23(1):37-44.

Popkin, CL; and Council, FM. (1993). A comparison of alcohol-related driving behavior of white and nonwhite North Carolina drivers. Accident Analysis and Prevention 25(4):355-364.

Pristach, EA; Nochajski, TH; Wieczorek, WF; Miller, BA; and Greene, B. (1001). Psychiatric symptoms and DWI offenders. Alcohol and Alcoholism, Suppl. 1., pp. 493-496 (1):493-496.

Ross, HL; Howard, JM; Ganikos, ML; and Taylor, ED. (1991). Drunk driving among American Blacks and Hispanics. Accident Analysis and Prevention 23(1):1-11.

Saltz, RF. (1989). Research needs and opportunities in server intervention programs. Health Education Quarterly 16(3):429-438.

Sarvela, PD; Taylor, EL; Drolet, JC; and Newcomb, PR. (1988). Indicators of drinking and driving among university students. Health Education 19(5):72-77.

Shore, ER; McCoy, ML; Toonen, LA; and Kuntz, EJ. (1988). Arrests of women for driving under the influence. Journal of Studies on Alcohol 49(1):7-10.

Simpson, HM; and Mayhew, DR. (1992). The hard core drinking driver. Update. Ottawa, Ontario: Traffic Injury Research Foundation of Canada.

Soderstrom, CA; Birschbach, JM; and Dischinger, PC. (1990). Injured drivers and alcohol use: culpability, convictions, and pre- and post-crash driving history. Journal of Trauma 30(10):1208-1214.

Soderstrom, CA; Dischinger, PC; Ho, SM; and Soderstrom, MT. (1991). Alcohol use, driving records, and crash culpability among injured motorcycle drivers. In: Proceedings of the 35th Annual Conference of the Association for the Advancement of Automotive Medicine. Des Plaines, IL, 1991. pp 219-234. American Association for Automotive Medicine.

Soderstrom, CA; Dischinger, PC; Ho, SM; and Shankar, BS. (1990). A study of alcohol use among 165 injured motorcycle drivers treated at Maryland trauma centers: clinical and crash perspectives including crash culpability. Final report. Washington, D.C.: Office of Crashworthiness, National Highway Traffic Safety Administration.

Stacy, AW; Newcomb, MD; and Bentler, PM. (1991). Personality, problem drinking, and drunk driving: mediating, moderating, and direct-effect models. Journal of Personality and Social Psychology 60(5):795-811.

Stein, SK. (1989). Risk factors of sober and drunk drivers by time of day. Alcohol, Drugs and Driving 5(3):215-227.

Stoduto, G; Vingilis, E; Kapur, BM; Sheu, WJ; McLellan, BA; and Liban, CB. (1993). Alcohol and drug use among motor vehicle collision victims admitted to a regional trauma unit: demographic, injury, and crash characteristics. Accident Analysis and Prevention 25(4):411-420.

Sweedler, BM; and Quinlan, KE. (1990). Alcohol and drugs among fatally injured drivers of heavy trucks. In: Proceedings of the 11th ICADTS Conference, T89, National Safety Council. Chicago, IL, 1990. pp 332-336.

Tashima H.; and Helander, C. (1993). Legislative report on DUI offenders. In: State of California DMV. Research note Winter 1993/94. Sacramento, California: California Department of Motor Vehicles, Research & Development Section.

Transportation Research Board. (1993). Alcohol and other drugs in transportation - research needs for the next decade. Transportation Research Circular 408:1-114.

Transportation Research Board. (1993). Alcohol and other drugs - their role in transportation. Transportation Research Circular 413:1-30.

Turrisi, R; and Jaccard, J. (1992). Cognitive and attitudinal factors in the analysis of alternatives to drunk driving. Journal of Studies on Alcohol 53(5):405-414.

U.S. Department of Transportation, NHTSA. (1992). Target populations expert panel workshop. Internal report. Washington, DC: National Highway Traffic Safety Administration. (Unpublished.)

U.S. Department of Transportation, NHTSA. (1993). Tier 1 task force report on identification of target populations. Internal report. Washington, D.C.: National Highway Traffic Safety Administration. (Unpublished.)

U.S. Department of Transportation, NHTSA. (1997). Traffic safety facts 1996. Washington, DC: National Highway Traffic Safety Administration.

Valverius, MR. (1989). Women, alcohol, drugs and traffic. Proceedings of the international workshop. In: Proceedings of the Women, Alcohol, Drugs and Traffic International Workshop. Stockholm, Sweden, September 29-30, 1988. Stockholm, Sweden: International Committee on Alcohol, Drugs and Traffic Safety.

Vegega, ME; and Klein, TM. (1991). Safety belt use among drivers involved in alcohol-related fatal motor-vehicle crashes - United States 1982-1989. Morbidity and Mortality Weekly Report 40(24):397-400.

Vingilis, E. (In press). Moderate drinking and traffic crashes: a case for health or safety? Contemporary Drug Problems.

Vingilis, E; and Adlai, E. (1990). The structure of problem behaviour among Ontario high school students: a confirmatory-factor analysis. Health Education Research 5(2):151-160.

Vingilis, E; Stoduto, G; Macartney-Filgate, MS; Liban, CB; and McLellan, BA. (1994). Psychosocial characteristics of alcohol-involved and nonalcohol-involved seriously injured drivers. Accident Analysis and Prevention 26(1):1-12.

Vingilis, E; Wasylyk, N; Blefgen, H; and Shamai, S. (1993). The Ontario 12-hour administrative licence suspension law against drinking-drivers; the Ontario provincial police assessment of offence and drivers' characteristics. Journal of Traffic Medicine 21(2):59-64.

Watson, WA; and Garriott, JC. (1992). Alcohol and motorcycle riders: a comparison of motorcycle and car/truck DWIs. Veterinary and Human Toxicology 34(3):213-215.

Wells-Parker, E; Pang, MG; Anderson, BJ; McMillen, DL; and Miller, DI. (1991). Female DUI offenders: a comparison to male counterparts and an examination of the effects of intervention on women's recidivism rates. Journal of Studies on Alcohol 52(2):142-147.

Wieczorek, WF. (1992). Treatment histories of severe DWI offenders. In: Proceedings of the Alcohol, Drugs and Traffic Safety Conference. Cologne, Germany: Vertag TUV Rheinland GmbH. 305-310.

Wieczorek, WF; Miller, BA; and Nochajski, TH. (1991). The limited utility of BAC for identifying alcohol-related problems among DWI offenders. Journal of Studies on Alcohol, Vol. 53, 1992, pp. 415-419 53:415-419.

Wieczorek, WF; Miller, BA; and Nochajski, TH. (1992). Multiple and single location drinking among DWI offenders referred for alcoholism evaluation. American Journal of Drug and Alcohol Abuse, Vol. 18, No. 1, 1992, pp. 103-116 18(1):103-116.

Wieczorek, WF; and Miller, BA. (1992). Preliminary typology designed for treatment matching of driving-while-intoxicated offenders. Journal of Consulting and Clinical Psychology 60(5):757-765.

Wieczorek, WF; Mirand, AL; and Callahan, BA. (In press). Perception of the risk of arrest for drinking and driving.

Wieczorek, WF; Welte, JW; and Abel, EL. (1990). Alcohol, drugs and murder: a study of convicted homicide offenders. Journal of Criminal Justice, Vol. 18, 1990, pp. 217-227 18:217-227.

Wilson, RJ. (1992). Convicted impaired drivers and high-risk drivers: how similar are they? Journal of Studies on Alcohol 53(4):335-344.

Windle, M; and Miller, BA. (1989). Alcoholism and depressive symptomatology among convicted DWI men and women. Journal of Studies on Alcohol 50(5):406-413.

Zobeck, TS; Elliott, SD; Grant, BF; and Bertolucci, D. (1991). Surveillance report no. 17. Trends in alcohol-related fatal traffic crashes, United States: 1977 - 1988. Rockville, MD: National Institute on Alcohol Abuse and Alcoholism.

OTHER ARTICLES AND REFERENCES

Allen, TC. (1991). A study of university students regarding driving under the influence. Campus Law Enforcement Journal 21(2):34-35.

Basch, CE; DeCicco, IM; and Malfetti, JL. (1989). A focus group study on decision processes of young drivers: reasons that may support a decision to drink and drive. Health Education Quarterly 16(3):389-396.

Beerman, KA; Smith, MM; and Hall, RL. (1988). Predictors of recidivism in DUIIs. Journal of Studies on Alcohol 49(5):443-449.

Dischinger, PC; Soderstrom, CA; Shankar, BS; Cowley, RA; and Smialke, JE. (1988). The relationship between use of alcohol and place of death in vehicular fatalities. In: Proceedings of the 32nd Annual Conference of the Association for the Advancement of Automotive Medicine. Des Plaines, IL, 1988. pp 299-311. American Association for Automotive Medicine.

Gabella, B; Reiner, KL; Hoffman, RE; Cook, M; and Stallones, L. (1993). Relationship of helmet use and head injuries among motorcycle crash victims in El Paso County, Colorado, 1989-1990. In: Association for the Advancement of Automotive Medicine. 36th Annual Conference. Proceedings. Des Plaines, IL, 1993. Pp. 51-60.

Galdabini, TV. (1988). Identification of high risk traffic accident populations in Washington. Olympia, Washington: Washington Traffic Safety Commission.

Gjerde, H. (1988). Alcohol consumption levels among drunken drivers: studies of biological markers of excessive drinking. Oslo University, Norway: National Institute of Forensic Toxicology.

Haberman, PW; and Green, RE. (1992). Driver fatalities and DUI offenders in New Jersey. International Journal of the Addictions 27(6):675-681.

Jones, RK; and Joscelyn, KB. (1978). Alcohol and highway safety 1978: A review of the state-of-knowledge. Washington, DC: National Highway Traffic Safety Administration.

Jones, RK; and Lacey, JT (1989). Alcohol and highway safety 1989: A review of the state of knowledge. Washington, DC: National Highway Traffic Safety Administration.

Kirby, JM; Maul, KI; and Fain, W. (1992). Comparability of alcohol and drug use in injured drivers. Southern Medical Journal 85(8):800-802.

Kline, MV; Bacon, JD; and Greenest, R. (1988). The dual participants: a high risk drinking driver target group. Journal of Drug Education 18(3):201-210.

Klitzner, M; Resister, C; Gruenewald, P; and Blasinsky, M. (1987). Determinants of youth attitudes and skills towards which drinking/driving prevention programs should be directed. Washington, DC: National Highway Traffic Safety Administration.

Martin, NG; and Boomsma, DI. (1989). Willingness to drive when drunk and personality: a twin study. Behavior Genetics 19(1):97-111.

McMillen, DL; Pang, MG; Wells-Parker, E; and Anderson, BJ. (1992). Alcohol, personality traits, and high risk driving: a comparison of young, drinking driver groups. Addictive Behaviors 17(6):525-532.

McMillen, DL; Pang, MG; Wells-Parker, E; and Anderson, BJ. (1991). Behavior and personality traits among DUI arrestees, nonarrested impaired drivers, and nonimpaired drivers. International Journal of the Addictions 26(2):227-235.

Mundt, JC; Ross, LE; and Harrington, HL. (1992). A modeling analysis of young drivers' judgements of accident risk due to alcohol use and other driving conditions. Journal of Studies on Alcohol 53(3):239-248.

National Transportation Safety Board. (1990). Safety study: fatigue, alcohol, other drugs, and medical factors in fatal-to-the-driver heavy truck crashes. Volume 1. Washington, D.C.: National Transportation Safety Board.

National Transportation Safety Board. (1990). Safety study: fatigue, alcohol, other drugs, and medical factors in fatal-to-the-driver heavy truck crashes. Volume 2. Washington, D.C.: National Transportation Safety Board.

Noordzij, PC; Meester, AC; and Verschuur, WL. (1988). Night-time driving: the use of seat-belts and alcohol. Ergonomics 31(4):663-668.

Parsons, SL; and Lock, JR. (1989). A survey of selected 1986 motorcycle fatalities in the state of Texas. Summary of accident characteristics. College Station, Texas: Texas Transportation Institute.

Sarvela, PD; Taylor, EL; Drolet, JC; and Newcomb, PR. (1988). Indicators of drinking and driving among university students. Health Education 19(5):72-77.

Snow, RW. (1988). Sociodemographic characteristics and drinking locations of convicted drunken drivers. Addictive Behaviors 13(1):119-122.

Thurman, Q; Jackson, S; and Zhao, J. (1993). Drunk-driving research and innovation - a factorial survey study of decisions to drink and drive. Social Science Research 22(3):245-264.

Transport Canada. (1992). Alcohol use by drivers fatally injured in motor vehicle accidents: 1990 and the past ten years. Ottawa, Ontario: Road and Motor Vehicle Traffic Safety Branch, Transport Canada.

Turrisi, R; and Jaccard, J. (1991). Judgment processes relevant to drunk driving. Journal of Applied Social Psychology 21(2):89-118.

U.S. Department of Transportation. (1968). Alcohol and highway safety. Report to the U.S. Congress. Washington, DC: U.S. Government Printing Office.

U.S. Department of Transportation, NHTSA. (1985). Alcohol and highway safety 1984: A review of the state of the knowledge. Washington, DC: National Highway Traffic Safety Administration.

Vegega, ME; and Klitzner, MD. (1989). Drinking and driving among youth: a study of situational risk factors. Health Education Quarterly 16(3):373-388.

Veneziano, C; and Veneziano, J. (1992). Psychosocial characteristics of persons convicted of driving while intoxicated. Psychological Reports 70(3, Pt. 2): 1123-1130.

Wieczorek, WF; Miller, BA; and Nochajski, TH. (1989). Bar versus home drinkers: different subgroups of problem-drinker drivers. In: The problem-drinker driver project. Research note 89-6. Albany, New York: New York State Division of Alcoholism and Alcohol Abuse.

Wieczorek, WF; Miller, BA; and Nochajski, TH. (1991). Multiple location drinking and problem behavior among DWI offenders: a replication. In: The problem-drinker driver project. Research note 91-2. Albany, New York: New York State Division of Alcoholism and Alcohol Abuse.

Williams, AF; and Lund, AK. (1990). Alcohol impaired driving and crashes involving alcohol in the United States during the 1970s and 1980s. In: Proceedings of the 11th ICADTS Conference, T89, National Safety Council. Chicago, IL, 1990. pp 101-105.

Wilson, RJ; and Mann eds., RE. (1990). Drinking and driving: advances in research and prevention. New York, New York: The Guilford Press.

Wolfe, AC. (1990). Random roadside surveys to measure the incidence of drunk driving. In: Proceedings of the 11th ICADTS Conference, T89, National Safety Council. Chicago, IL, 1990. pp 66-75.

Wolfe, AC. (1975). Characteristics of alcohol-impaired drivers. Presented at: The Automobile Engineering Meeting. Detroit, MI, 1975. Society of Automotive Engineers.

Yu, J; and Williford, WR. (1993). Alcohol and risk/sensation seeking - specifying a causal model on high-risk driving. Journal of Addictive Diseases 12(1): 79-96.