Hazardous materials transportation by road: trends and problems in risk assessment and emergency planning

Hazardous material transportation poses obvious hazards to environment, general public and response personnel. In this context, risk reduction can be achieved by analyzing and designing correctly the routing of shipments, by proper risk assessment procedure. HazMat transportation risk management must include appropriate emergency response services, limiting accident consequences. This paper presents a quantitative risk assessment approach to HazMat transportation, starting from an historical statistical analysis on road accidents. A methodological approach for the assessment of standard vehicle and dangerous good truck flows was applied to a pilot area in the North of Italy, allowing a statistical reinforced evaluation of route intrinsic enhancing/mitigating parameters. The results evidence the distribution of the risk along the different routes and the localization of high spots, with good accuracy and precision. Preventive and mitigating risk measures are discussed in depth, with particular reference to the optimization of emergency equipment (number of prompt action vehicles) by means of an unambiguous and consistent selection criterion that allows reduction of intervention time. Different risk mitigation options, based on changing route or designing alternative slip roads, in transport corridors or tunnels, are investigated as well. The presented approach can represent a useful tool not only to estimate transport risk, but also to define strategies for the reduction of risk (i.e. distribution and limitation of ADR road traffic, improvement of highway section, design of alternative routes) and emergency management.