ABSTRACT
A sizeable body of road safety research has been conducted that utilises the Manchester Driver Behaviour Questionnaire (DBQ) to examine different types of driving behaviours among various driving populations. The DBQ originally constituted 50 items comprising five types of aberrant driver behaviour: slips; mistakes; lapses; unintended violations and deliberate violations (Reason, Manstead, Stradling, Baxter and Campbell, 1990) with the focus primarily on two distinct behaviours classified as either errors or violations. Errors consisted of actions and mistakes that were not premeditated, while violations were those behaviours deemed to be deliberate deviations from safe driving practices. A series of modifications to the original DBQ scale (Lawton, Parker, Stradling and Manstead, 1997) facilitated the identification of other factors believed to contribute to driver violations. The addition of a new factor named “aggressive violations” allowed researchers to measure interpersonally aggressive actions such as hostility towards other road users or driving in an aggressive manner.
