GIS supported transportation risk analysis approach

The work presents a methodology for performing transportation risk analysis (TRA) for hazardous materials travelling on road and rail vehicles based on the application of CPQRA techniques combined with the use of a Geographical Information System (GIS). This last allows to accurately account for the relevant territorial information (accident rate, population, meteorological conditions, etc.) which continuously change along the route. The methodology was applied to the Italian road and rail network, first dividing them into segments, some hundreds meters long, and then processing the available data to link the pertinent detailed information to each segment. A product data bank was also established where the main data concerning the expected accidental scenario evolution for each substance and transportation mode are collected. Such data were separately derived from the analysis of some accident data banks (MIDHAS, fire brigades, etc.) and by performing a consequence analysis on the expected outcome cases following two typical release scenarios in order to define their respective impact zones under some reference meteorological conditions. By combining the territorial information relevant to the route and the product data relevant to the examined transportation case a tool was obtained which enables fast and reliable estimates of the societal risk (F-N curve). The tool can be used for risk management, by planning transportation mode and routes based on the relevant risks, but also in emergency, since the impact zones of the expected outcome cases can be immediately visualized on the GIS maps, as well as the location of the available response teams (fire brigades, police stations, hospitals, etc.)