Transport of hazardous materials (hazmat) is a worldwide problem of growing interest, mainly because of the increasing transported volumes of materials that can be classified as hazardous. When dealing with these issues, many problems are still open; among them one can cite:

• technological problems linked to the safety of hazmat shipment, delivery and storage;
• monitoring and control of vehicles transporting hazmat on the road infrastructures;
• definition of tools and standardized procedures for emergency management;
• characterization of the risk induced over the territory by hazmat transport for planning and prevention purposes.

Despite several significant contributions, at the moment, in the literature, a shared and well established definition of hazmat transport risk can not be found.

CIMA Foundation works for the definition of a framework for hazmat risk assessment
The work of CIMA Foundation is aimed to contribute to the establishment of a common framework as regards hazmat transport risk assessment, as regards its evaluation and quantification, as well as the development of strategies allowing the mitigation of its impacts.
Nowadays, several hazmat risk indexes or approaches have been proposed and used in literature, and researchers from CIMA Foundation participated to this activity. Nevertheless, in the last years the goal of better understanding the key elements driving a suitable risk definition is more and more urgent. Accidents involving hazardous materials are in fact usually treated as low probability – high impact events. This is certainly true when considering accidents involving deaths or serious injuries, but accidents impacting only goods, services or the environment are much more frequent.
Current work is thus oriented to understand if these two typologies of accidents can be treated by analogous methodological tools, or if it is necessary to introduce a stronger probabilistic connotation for dealing with accidents impacting on the environment (without deaths/injuries). This step is the basis for the definition of support tools and decisional problems addressing hazmat risk at different time and space scales:

• characterization of the risk induced over the territory, taking into account the connection between hazmat risk and climatic indexes, and between hazard risk and natural hazards;
• identification of alternative paths for given origin-destination couples of hazmat transports, taking into account the opportunity of balancing the risk exposure of a given area;
• risk-based route planning and dynamic routing of hazmat vehicles.

When the most suitable actors (the decision makers and the other subjects involved in the decision making process), space and time scales for the decisional problems are identified, the macro-groups previously identified can be further subdivided into several specific decisional problems. The analysis of each specific decisional problem will lead to understand if the hazmat risk definition could be unique, or if a different balancing between life-oriented and environment-oriented components is necessary on the basis of the specific decisional problem under consideration.