The United States experienced 308 weather and climate related disasters since 1980, exceeding $2.085 trillion in physical losses and the loss of 14,492 lives. Between 1980 and 2020, the average number of billion-dollar events per year was 7.1; that number ballooned to 16.2 billion-dollar events per year on average between 2016 and 2020 (adjusted for Consumer Price Index). The most billion-dollar weather and climate related disasters occurred in 2020, with 22 billion-dollar events totaling $246.7 billion in losses and 553 deaths. As of September 2021, the current year is looking to break the record set in 2020, having experienced 18 billion-dollar events to date (Billion-Dollar Weather and Climate Disasters: Overview | National Centers for Environmental Information (NCEI) (www.noaa.gov )). In addition, the recently published TRB Consensus Study on Resilience Metrics notes that six of the world’s 10 most costly natural disasters in 2020 occurred in the United States (TRB Resilience Metrics Consensus Study, 2021). With this level of impact on the nation’s infrastructure, transportation agencies need consistent methods to support decision-making to address stressors such as extreme weather and climate change in planning, design, maintenance, and operations.
The TRB Resilience Metrics Consensus Study 2021 calls for the establishment of standard methods of analysis to support benefit-cost assessment to allow agencies to understand the “buy-down” of risk from capital and maintenance investments. In addition, the study calls on Congress to consider requiring all federal funding candidate projects that involve long-lived assets requirement undergo well-defined resilience assessments that account for changing risks of natural hazards and environmental conditions stemming from climate change. The proposed project will enable the development of industry adopted standard methods of quantitative analysis.
A concerted level of commitment is needed to develop a single manual to serve as the “go-to” for quantitative analysis of financial risk to agency assets and the traveling public from extreme weather and climate change. Like the Highway Capacity Manual and the Highway Safety Manual, a single resource is needed to ensure consistent methods of analysis between projects and agencies, and to ensure adoption of robust quantitative methods to support benefit-cost analysis and decision-making. A single manual can enable stakeholders at all levels to compare project investments on a level playing field—using the same models, same assumptions, and same thresholds of performance. A single manual also can support the instruction of how to address extreme weather and climate change in planning and engineering curriculum at universities ensuring future transportation professionals are equipped with the skills needed to support the adoption of such methods into practice. Finally, a single manual can enable the incorporation of extreme weather and climate change considerations in professional engineering examinations to further institutionalize these concepts in future design and decision-making.
This project will be Phase 1 of a multi-phase project. The conceptual framework for the new manual and the additional research needed beyond Phase 1 was developed in NCHRP Project 23-09, “Scoping Study to Develop the Basis for a Highway Standard to Conduct an All-Hazards Risk and Resilience Analysis” and NCHRP Project 20-123(04), “Development of a Risk Management Strategic Plan and Research Roadmap.” This undertaking will result in an industry “standard” for all-hazards risk and resilience analysis for use in design, maintenance, and planning decision-making.
The objective of this project is to complete Phase 1 and should include the development of the AASHTO Transportation Asset Risk and Resilience Manual and should (1) establish quantitative assessment methodology for top priority threats and assets (e.g., culverts and flooding); (2) develop historical data capture process quantitative analysis methods; (3) develop quantitative resilience assessment methodology; and (4) establish performance metrics and thresholds for resilience and risk tolerance, and provide guidance on reducing risk and improving resilience.
Subsequent phases may focus on implementation of the Phase 1 Transportation Risk and Resilience Manual, development of tools and resources to support the Manual, and development of stand-alone, open source computer script that can work within a GIS (define) environment to automate Manual calculations across multiple assets and threats in a geo-spatial setting. Other topics to be considered in future phases include developing spreadsheet-based tools to automate Manual calculations across multiple assets and threats in a spreadsheet application, selecting performance metrics for evaluating the effectiveness of risk mitigation, incorporating risk management into maintenance practice, developing new performance metrics for risk management, and assessing the impact of common risks on federal reporting metrics.
Transportation owners and operators are responsible for the transportation system and the delivery of services and functions through the management of that system. There are inherent risks involved with the management of these systems, notwithstanding aging infrastructure, and fiscally constrained resources. Many agencies are moving toward performance-based resource allocation while simultaneously recognizing risks that may undermine their strategic goals. As these risks affect every component of a transportation system, accurately accounting for and addressing these risks within a transportation agency’s enterprise-wide management program is the goal that currently lacks analysis tools.
Investing in risk and resilience strategies and enhanced recovery to reduce or eliminate the impact of external events is also paramount to ensure a thriving, viable transportation system. Risk management requires the identification and assessment of potential threats and hazards, asset vulnerabilities from applicable threats, an evaluation of potential mitigation actions to reduce risk, a clear and easy to implement process to prioritize mitigation activities, and investment that aligns with agency strategic and performance goals. Asset management, and more recently performance management, has been an ongoing focus of many research efforts. However, guidance for analytical risk assessment methods to support risk-based asset management processes is lagging. Risk assessment processes, methods, and tools are needed to integrate risk management into asset and performance management systems. In addition, an understanding of the relationship between risks and system resilience is lacking.
Future research can expand threats analyzed; assets analyzed; climate projections; life cycle cost; remaining life consideration of assets; environmental impacts, etc.
The $4,000,000 project allocation includes $500,000 provided by the U.S. DOT Office of the Assistant Secretary for Research and Technology.