Analysis of past accidents triggered by physical security attacks to dangerous goods transportation systems

The transportation of hazardous materials may represent an attractive target for intentional physical attacks able of escalating into major accidents. This work presents a systematic analysis of security-related events occurred during the transport of dangerous goods. The collected dataset, a total of 373 events, is analysed to identify the threat types, attack modes, release dimensions, and the resulting final scenarios. Two major contributions result from this analysis: (i) the development of tailored bow-tie diagrams to represent typical sequences of security attacks to the dangerous goods transportation systems, and (ii) the estimation of the security attack rate, suitable for integration into quantitative risk assessment frameworks. The findings reveals that the security attack rate to hazardous material transportation is between one and two orders of magnitude higher than that of safety accidents. This result emphasize that security aspects should be specifically addressed along with safety in any comprehensive risk assessment of dangerous goods transportation systems.