In an exploratory postal survey of 711 drivers stratified by age, sex, annual mileage, and accident involvement, decision-making style was measured using a Decision-Making Questionnaire (DMQ) and driving style was assessed using a Driving Style Questionnaire (DSQ). Responses to 21 items of the DMQ formed seven independent and internally coherent dimensions according to a principal components (PC) analysis. These were labelled: control, thoroughness, instinctiveness, social resistance, hesitancy, perfectionism, and idealism. PC analysis also revealed that responses to 15 items of the DSQ formed six independent dimensions of driving style. These were labelled: speed. calmness, social resistance, focus, planning, and deviance. Multiple regression analysis indicated that drivers of 60 years and under who scored lower on thoroughness were at greater risk of a traffic accident and that this relationship was mediated by faster driving. This relationship was independent of age, sex, annual mileage, and all other factors measured. In the drivers over 60 years, lower thoroughness, greater hesitancy, and faster driving were independently associated with higher accident rates independent of all other factors measured. The results provide preliminary support for the view that people import aspects of their general decision-making style into the driving situation, and that in so doing they put themselves at differential risk of having a road traffic accident.