Evaluating the “Unknown” Risks of Vehicular Tunnel Fires Through the Rubric and Matrix Method

Abstract

Major tunnel fires are rare, unpredictable, and often devastating. History provides examples of major tunnel operations that had incorporated various elements of Fire Life Safety (FLS) and Emergency Preparation and Management (EPM) into the design, infrastructure, operations, and emergency response capability. Yet, tunnel operators have often found out in hindsight that their preparations were not sufficient. Factors that may either minimize or worsen a catastrophic event can be estimated and evaluated. Risk analysis is used extensively in various industries for both quantitative and qualitative applications. Formal, quantitative risk analysis uses “known-unknowns” and enables the use of quantitative analysis of probabilities and consequences. Uncertainty analysis deals with “unknown-unknowns” and is restricted to qualitative analysis. Researchers at the Colorado School of Mines have created a unique process to evaluate qualitative risks through an Emergency Preparedness Rubric and an Event Consequence Matrix method. The process was applied cross the functional areas of FLS-EPM and the tunnel’s functional components that are important to safety. The method is universally adaptable and enables stakeholders involved in tunnel design, operations, management, and emergency response to identify and communicate areas where the systems and components are insufficient. This paper will address the approach, methodology, and results for a representative focus case.