The aggressive behavior index (αs = 0.85 to 0.89, current α = 0.87) assesses the frequency (0 to 5+, 5+ being treated as a 5 in analyses) who reported engaging in each of 13 aggressive driving behaviors in the past 3 months (e.g., yelling at another driver or cutting off in anger). The risk behavior index (αs = 0.83 to 0.86, current α = 0.86) includes reports on the frequency (0 to 5+) with which the person engaged in 15 risky driving behaviors in the past 3 months (for example, driving while intoxicated, driving without a seat belt, or speeding 20 mph or more over the limit). Aggressive and risky behaviors are positively correlated with each other, driving anger, hostile driving-related thoughts, and verbal, physical, and vehicular forms of expression of driving anger (Deffenbacher et al. 2002a , 2003d, 2004). The Driving Anger Expressions Inventory (DAX) is an instrument used to measure how people express their anger while driving. (Deffenbacher, Deffenbacher, Lynch, Oetting, & Swaim, 2001; Deffenbacher, Lynch, Oetting, & Swaim, 2002; Deffenbacher, White, & Lynch, 2004a; Deffenbacher, White, & Lynch, 2004b; González-Iglesias, Gómez-Fraguela, & Luengo- Martín, 2012; Dahlen, Edwards, Tubré, Zyphur, & Warren, 2012; The DAX was developed because not only can a person's level of anger have negative consequences on the road, but the way a driver expresses it Anger on the road can also have a major effect (Deffenbacher et al., 2002, 2004a). Not only can the way a person expresses their anger affect the safety of the driver, but also that of other road users (Kazemeini et al.). al., 2013). People also have different ways of expressing anger even though...... middle of article...... research part F: traffic psychology and behavior, 15 (4). ), pp. 404--412. (González-Iglesias et al., 2012) Ghanbari-e-Hashem-Abadi, B. and Safarzadeh, A. (2013). Mindfulness-based cognitive group therapy vs. cognitive-behavioral group therapy as a treatment for anger and aggression among Iranian taxi drivers. Psychology, 4, 638-644. doi: 10.4236/psych.2013.48091.(Kazemeini, Ghanbari-e-Hashem-Abadi & Safarzadeh, 2013)(Kazemeini et al., 2013)Dahlen, E., Edwards, B., Tubr'E, T., Zyphur, M. and Warren, C. 2012. A look behind the wheel: An investigation of personality predictors of aggressive driving. Accident analysis and prevention, 45 pp. 1--9. (Dahlen, Edwards, Tubré, Zyphur and Warren, 2012)(Dahlen et al.., 2012)