The risk modelling research presented in this paper uses time series  constructed on monthly data and over a long period, is designed to further  the analysis of the development of road risk, by bringing together all the  explanatory factors of risk and risk exposure that appear at an infra annual  rate. The choice of monthly periodicity, which is the product of a compromise  between the variability and availability of existing data and that of the  determinants - weather and time of year conditions, traffic flow or its  substitutes (economic activity, prices, and network development), behavioural  variables and road safety measures - position this approach midway between  the modelling of daily fluctuations and the modelling of long-term trends.  We will present a version of the model limited to two types of network, main  roads and toll motorways and then also extend to the whole network. We will  first describe the structure of the model as a whole, and then go on to  outline the main results: the outcome of tests of hypothesis related to  econometric specification, the values for the indicators' elasticity to their  determinants, showing their development over the period, and the simulations  carried out in the short term. Lastly, we will discuss these findings and  suggest avenues of enquiry for continuing this research.