Consistency and stability of risk indicators: The case of road infrastructures

Over the last decade, the World Road Association – PIARC and several European research projects, among which Ecoroads, have encouraged a promising reflection on risk analysis methods, acceptance criteria and safety practices applied to the road system. The goal of this research activity is the definition of best practice for safety analysis and management to be applied to network TERN (Trans European Road Network). Quantitative Risk Analysis (QRA) provides much information on safety management. Nevertheless, the potential fragility of the method, stochastic uncertainties (both parameters and models), and ethical aspect of criteria must be adequately analyzed. This paper focuses on all these aspects, assessing the reliability of QRA due to modeling errors and statistical errors, and assessing the statistical consistency of Risk Indicators of QRA.