Abstract
The study concentrates on the etiological concept of risk, i. e. that which expresses a causal relationship, the risk will be evaluated by means of two different measures of risk exposure: distance travelled and driving-time in order to highlight the consequences of choosing a particular measurement, and the effect of the driving speed. It is shown through the analysis of the speed of young drivers and male drivers that different interpretations appear, according to how deeply we go into the detail of the data used.