The current study aimed to compare driving violations and driving errors of addicted, under-treatment and healthy drivers. Also, the influence of aberrant driving behavior on traffic safety (accidents and tickets) for each group was assessed. A total of 240 volunteers filled up Driving Behavior Questionnaire and a demographic questionnaire asking about driving experience and history of substance was used. ANCOVA and MANCOVA with age, gender, education, and hours of driving per week, and the years of driving experience as covariates indicated that compared to healthy drivers, addicted and under-treatment drivers reported higher rate of aggressive violations, ordinary violations, errors, lapses, accidents and tickets. Among addicted there was significant relationship between the number of accidents and driving errors. Their number of tickets was related to ordinary driving violations. For the under-treatment group, the number of accidents were related to ordinary violations, aggressive violations, errors and lapses. Their number of tickets was related to aggressive violations, ordinary violations and errors. For healthy individuals none of the correlations were significant. Addicted and under-treatment individuals violate traffic regulations and drive erroneously more than healthy individuals, resulting in decrease in traffic safety.