A multivaried modelling of accident risks on the national road network (highways and motorways) has been carried out month by month for the period 1975-1992. The determinant variables of risk of the various types - economic (exposure to risk in the form of light and heavy vehicle traffic, economic growth, prices, consistency of the network), meteorological, and behavioural (speed travelled and level of safety belt usage) have been considered simultaneously for main roads and motorways under concession while also incorporating the cross-over effects between the two networks. The model distinguishes short and long term effects and gives risk elasticities to these determinants which incorporate this dual element. The contribution of the vector modelling is brought out through an unvaried modelling of the accident risk on each of the two networks considered individually. The graphs and numerical results were obtained from SAS Software, with a specific chronological algorithm with external variables for the vector modelling.
Samenvatting