8: Comparing Six DRAG-Type Models

Over the past few years, different transport research establishments have adopted a common method for modelling road safety indicators. The Road Demand, Accidents and Their Severity (DRAG model: modèle de la Demande Routière des Accidents et de leur Gravité) model, conceived by Marc Gaudry in Quebec in the mid-1980s, is the reference. Germany, France, Norway, Sweden and the State of California have recently taken up this approach albeit adapting it to their statistical particularities, on the one hand, and to their socio-economic and political environments, on the other (cf. Table 1).

The findings are expressed in terms of the elasticities of risk indicators as a function of explanatory variables that are common to the different models in the DRAG family. The risk factors retained here are those, which appear to be the most important, and which are shared between several models, so that a comparison can be made of their effects. These factors are classified by theme: Risk exposure (section 1), driver behaviour (section 2) and economic variables, divided between households’ economic situation and the factors that influence the frequency and distance of people’s journeys (section 3).