Risk-Based Management of Ancillary Transportation Assets: Applying the Delphi Method to Estimate the Risk of Failure

摘要

Although their consequences of failure can sometimes be catastrophic, ancillary transportationassets such as earth retaining structures, culverts, guardrails, embankments, rock-fall supports,and traffic signals and their hardware have received relatively less focus in transportation assetmanagement to date because of their lower rates of failure. Nevertheless, some notable failuresaround the country have resulted in loss of life, economic benefits as well as public trust. Tominimize these kinds of negative outcomes, transportation agencies have made efforts tosystematically incorporate these asset classes in their asset management systems. However, thechallenge is sometimes to identify which asset classes are of higher priority as agencies typicallycannot address all assets at once. In the context of the national surface transportation legislation:Moving Ahead for Progress in the 21st century Act, which emphasizes risk-based assetmanagement, this paper proposes a risk-analysis approach, employing the Delphi method, toprioritize asset classes that are under the jurisdiction of a transportation agency for inclusion intoformal asset management programs. A Delphi study was conducted to identify asset classes thatpose the highest levels of threat to the goals of a transportation agency and to rank the relativelikelihoods of occurrence of these threats. The paper demonstrates that the Delphi method canbe used to gather expert opinion to identify and prioritize high-risk ancillary transportation assetclasses within a transportation network.