Risk Assessment of Operation Safety in Freeway Tunnels: An Evaluation Approach Using Multiple Safety Indices

The freeway tunnel accidents in China over the last decade have attracted more attention on the operation safety in freeway tunnels. To explore the safety of the traffic driving environment, a risk-assessment approach based on Multiple Safety Indices (MSI) has been proposed. First, the MSI were built upon road, traffic operation, traffic engineering facilities, and weather environment. Then, the Delphi method was used to execute a sensitivity analysis for MSI, so as to improve their rationality. Second, to derive the weights of indices, the knowledge of experts and the implied information on data were taken into account. Moreover, for the sake of revealing the subjectivity of evaluation levels and objectivity of measured data, the weights were contributed in depth by synthesizing the result of analytic hierarchy process and entropy method. Finally, the fuzzy comprehensive evaluation was involved to assess the operation safety in freeway tunnels. In particular, the operation security levels were determined by the maximum fuzzy membership. By taking the example of LiuWu Freeway Tunnel Groups, the research results suggest that the method in this article can provide a good theoretical guidance for the analysis and risk assessment of traffic safety.