Aggressive driving measures

Figure 9-3. Aggressive driving is not a new phenomenon. (Painting by Claude Guilot, 1707). Measures of aggressive driving and road rage...

Two techniques have been used to measure aggressive driving observations and questionnaire-based self-reports. Obviously observations of specific aggressive behaviors are more valid and objective than self-reports, but tiiey are more difficult to conduct. Consequently we must rely on both behavioral observations and questionnaires to understand aggressive driving. 

Questionnaire-based measures of aggressive driving. The rationale behind traffic laws and regulations is that the transportation system is just that a system. Its tolerance - from the perspective of expected driver behavior - is defined by the list of traffic violations or infringements. It is also implicitly assumed that drivers v/ho commit many traffic violations are more likely to be involved in crashes than those o do not. This assumption has partial validity from studies that examined die relationship between violations and crashes, though die strength of the relationship varies as a fimction of the violations studied (Cooper, 1997). 

Table 9-3. A scale for measuring aggressive driving tendencies developed by James and Nahl (2000), and the percent of Americmi drivers who agree with each item (reprinted from Wells-Paiker et aL, 2002, with permission from Elsevier).

A questionnaire designed to measure driving aggression more directly was developed by James and Nahl (2000), and reproduced in Table 9-3. The scale consists of 17 statements, ranging from very mild expressions of aggression to very extreme ones. As in Reason s questionnaire, the respondent s task is to state the extent to which these statements apply to him or her. 

Psychologists have focused primarily on who is the aggressive driver Why does he or she behave that way And how is this behavior related to more basic measures of personality that extend to multiple domains, and not just driving Obviously, not all drivers react to a frustrating event in the same manner, and the differences among the drivers — given the same situation - are attributed to their personality. 

---