Communicating Multiobjective Risk: A New Geotechnical Need for Transportation

Risk-based asset and performance management was enacted into law for federally funded highway projects in 2012 and has also become part of the business plans of many highway agencies. Implementation guidelines for transportation asset management were published by AASHTO in 2011 to help states in this regard. Parallel to these developments, geotechnical asset management approaches were being explored by some municipalities and states and by TRB through the formation of a subcommittee and specialty conferences. A result of these concurrent activities and the shared interest is the need to convey risk. Given that agencies own many types of assets (including geotechnical ones), that the highway legislation and agency business plans contain multiple performance goals, and that AASHTO identifies multiple risk types, the process of conveying risk is difficult. Although risk is of multiple types and pertains to multiple assets, an important realization in the practice of multigoal performance management is that risk pertains to multiple goals. The risk to an agency’s performance objectives from geotechnical assets includes safety, but also includes objectives such as infrastructure condition, congestion mitigation, environmental sustainability, and others. The risk cube introduced here is a three-dimensional visualization of those risks. The risk cube allows recognition of locations where risks exist, and the cube allows for clear communication, facilitating collaboration among asset managers and other practitioners and helping ensure that agencies make well-informed risk-based decisions for their programs. Geotechnical examples are used here, but nothing is inherently geotechnical about the approach.