| Road accidents involving hazardous materials present, due to such materials, serious risk of exacerbations. Thus it is essential to study their transport, to enable the authorities to regulate effectively and safely this transport sector. The present study aims to determine the influence of hazardous materials presence on the heavy vehicle accident in Quebec, using a statistical analysis of data and spatial analysis.;A comparative analysis of common fields was conducted using statistical tools such as descriptive statistics, charts and hypothesis testing. First the field "date" was studied. The analysis of the number of accidents per year did not reveal any clear trend. It seems that years with high proportion of heavy vehicle accidents are also years of high hazmat vehicle accident rates, but the link is not very marked. However, in equal proportions, hazmat accidents annual variations are more than 2 times superior to the annual variations of global base. Moreover, the winter is especially conducive to hazmat accidents with particularly high accident rate. The hourly distribution obtained is similar between the two databases, with a majority of accidents during the day, with two peaks around 20h and 14h and a pause at noon.;Then the quantitative fields have been studied. The number of vehicles involved appears significantly lower in the case of hazmat accidents with a difference of 0.2 vehicles per accident, reflecting a higher proportion of accidents involving a single vehicle. Analysis of the "speed limit" field seems to show that hazmat accidents occur on slower roads. However, this result must be qualified since in nearly 50% of accident reports this information is missing. The results of human consequences analysis are more reliable. We get that hazmat accidents are proportionally more fatal and cause more injuries than global accidents and that the probability of having a large number of people involved is higher for a hazmat accident.;This statistical analysis was completed by the study of qualitative fields, which can point out some differences in conditions or circumstances favoring accidents. Thus, hazmat accidents are more often due to an exit route than the global ones, although the most frequent is, in both cases, a collision between two vehicles. In addition, several fields emphasize the greater danger of DM transportation in winter conditions, with for example more accidents in the snow or on icy or snowy surfaces for the hazmat base. Finally, hazmat accidents occur most often in rural or forest areas than general accidents, which occur mainly in commercial areas.;In the second part of this study, a spatial analysis of accident distributions was conducted. The distributions obtained show that accidents are concentrated in the populated areas of Quebec, especially along the Saint-Laurent. The region with the largest number of hazmat accidents is the Monteregie with 20%. For the global base it is Montreal, which focuses the vast majority of accidents with 26% of accidents. The centrographic analysis confirms this observation, since the mean center of the global base is located closer to Montreal than hazmat base's one. This point also corresponds to that of the Quebec population. Hazmat accidents appear to be better distributed in Quebec and less related to population distribution, as confirmed by the standard deviation ellipses. The analysis of annual changes of the centers means position shows that the overall trend is to get closer to Montreal, particularly for global accidents base, the hazmat accidents centers means seem more random and vary over a larger surface from one year to another. An analysis of nearest neighbors confirms the larger scatter of hazmat accidents base with a value of the NNI over 10 times higher than the global base. The analysis of hotspots shows that with "large" hot spot distributions studies, the two distributions behave similarly. The main concentration of accidents is found around Montreal, as confirmed by the analysis of densities. On the contrary, when making groupings finer, differences appear. The highest concentration of global base's accidents is then highlighted, with ellipses NNH Level 2 covering a small part of the territory compared to the ellipses of the hazmat base. (Abstract shortened by UMI.)... |
