Winter Maintenance and Stakes as Regards Road Safety.

The Scientific and Technical Network of the Ministry for Equipment in France for more than one decade has developed a global approach for winter maintenance, whose objective is to make coherent the actions carried out on this field. If with the acquisition of knowledge and evolution of the practices at an organisation, progress is observed, it remains difficult to know if these changes improve road safety. There are few studies on this topic, but the figure of 1 to 2 % of fatalities occurring on roadways snow-covered or icy is often put forward. The quantification of accidents was carried out starting from the "National File of the Accidents", where it is recorded the accidents for which the surface quality was snow-covered or icy. The quality of these files is sometimes criticized, but for an approachof this type it is especially necessary to have a significant number of observations. The data (1993 to 2002) correspond to the 'modern' period of winter viability (circulars of 1994/1996, Improvement of the organization of Winter Maintenance, methods of follow-up, preventive treatments), wherethe quality of the service to the user can be considered stable. The whole of the killed or seriously injured was compared with the accidents wheresurface is snow-covered or icy according to various methods, per month, by years, by departments, etc.... The severity of the accidents was analyzed and the comparisons made between accidents on snow and ice. A research of the characteristics of the accidents starting from various parameters supplements this approach. These parameters are the longitudinal profile, the alignment, the period day/night, the site: rural area, urban area > 5000inhabitants, < 5000, and the type of network. This general assessment makes it possible to discover interesting elements, the accidents are not necessarily in the most rigorous climatic aera, the number of accidents increases in proportion in the inclined zones and the turns, at night and in rural areas. For the covering abstract see ITRD E143097.