Objective: Drinking and driving is a primary cause of traffic fatalities and it has been suggested that binge drinkers comprise a major portion of those drivers involved in drinking and driving accidents. Although several experimental studies have investigated the driving behavior of binge drinkers (particularly college students and/or young adults) under the influence of alcohol, few studies have focused on a comparison of sober driving behavior of the general population between binge and non-binge drinkers with a consideration of drivers' income levels. In addition, these studies have not taken other potentially influential factors into account such as socio economic status. Methods: A driving simulator study was conducted with a 2 x 2 factorial design (binge vs. non-binge drinker; low vs. high income). Sixty-two participants who were not under the influence of alcohol or drugs were asked to operate a driving simulator following traffic rules. Multiple aspects of participants' driving behaviors were measured in a sober driving situation. To control the potential effects of confounding factors, factors (e.g., age, gender, etc.) that were significantly correlated to the driving behavior were all entered into the multivariate analysis of variance (MANOVA) as covariates. Results: Significant interaction effects were found between effects of binge drinking and income levels. Analyses indicated that binge drinkersindependent of their income levelsexhibited more speeding exceedances and longer speeding duration than those of non-binge drinkers with a high income. Individuals characterized as non-binge drinkers with a low income also exhibited more speeding behaviors. Conclusion: Cognitive deficits and problems in vehicle control resulting from chronic alcohol consumption may impact binge drinkers' abilities to perform adequately, even in a sober driving situation. In addition, non-binge drinkers with a low income were more prone to make unsafe choices compared to non-binge drinkers with a high income. Further implications of the results in transportation safety and alcohol addiction were also discussed.
