SUMMARY

Transportation agencies, including the state Departments of Transportation (DOTs), are increasing their focus on resilience as they continue to manage the impacts of extreme weather and natural hazard variability on transportation infrastructure and communities that rely on them to sustain and improve their quality of life. As the integration and mainstreaming of resilience into agency functions continues to take hold, decision-makers need to be provided with an objective basis for taking investment, policy, and programmatic decisions that improve transportation system resilience. To enable this evaluation and an eventual transition to a performance-based planning and implementation approach for investing in resilience, state DOTs and other transportation agencies need approaches and tools to track the efficacy of resilience initiatives, projects, and investments. At the same time, resilience initiatives and actions need to be ascertained for their alignment with agency goals and objectives, while assessing how their benefits and outcomes are synchronized. This will require agencies and transportation practitioners to develop approaches to justify investments in resilience and benefits, while demonstrating how it advances the agency’s mission and goals.

Through the research conducted (NCHRP Project 23-26, Measuring Impacts and Performance of State DOT Resilience Efforts) and products developed as part of this effort, the research team focused on the key objectives of developing resilience performance measures (RPMs) and provide resources and guidance on selecting and deploying them to assess the effectiveness of resilience strategies. With these guiding objectives, the research team conducted a foundational review of literature and state of practice in the relevant areas of performance measurement in resilience, compiled specific agency needs and challenges and developed key products listed in the project objectives in a customized manner for practical adoption by agencies. These include a Compendium of RPMs and methods to demonstrate linkages to agency goals, objectives, and actions driving resilience initiatives at state DOTs. This research also highlighted and fulfilled a need to develop a process model – the Strategic Implementation Model (SIM) that could be implemented by practitioners by providing a systematic approach for state DOTs to identify, develop, and integrate RPMs into their agency processes.

Using SIM as the guiding process model, the research team developed a guide that provides transportation practitioners with a step-by-step, practical, hands-on experience in selecting, developing, and adopting RPMs to evaluate the effectiveness of resilience policies, programs, and project implementation at their agencies. The guide has been published as NCHRP Research Report 1159: Measuring Impacts and Performance of State DOT Resilience Efforts: A Guide. The guide and the Compendium of RPMs are complemented with RPM templates, which provide a blueprint for seven RPMs prioritized by the stakeholders and affirmed by the NCHRP Project 23-26 panel. These templates provide a detailed approach for each of these selected RPMs by stepping them through the SIM processes, providing guidance on crosscutting issues like data usability and analysis, community resilience considerations, communications, and implementation support. The Compendium of RPMs is presented in an interactive, filterable spreadsheet format, which can be queried based on the hazards and asset types they are most interested in, and the area of the DOT that may be best equipped to employ the RPM.

One key acknowledgement from the research team was the development of ongoing research on this topic. Specifically, transportation resilience research, which as an emerging body of work, helped to shape the various topics explored in NCHRP Project 23-26. These were highlighted in NCHRP Research Report 1159 “Looking Ahead” call-outs. NCHRP Research Report 1159 also includes a dedicated chapter that outlines potential gaps in existing research, along with ongoing and future research needed to address these gaps and deficiencies in current modeling, methods, and approaches.

This research also provided an opportunity for documenting the evolution of the field of transportation risk and resilience, specifically as they relate to assessment abilities, incorporating uncertainties into modeling and communicating it, and collecting ex-post and field data on performance of assets in changing

environments and effectiveness of resilience improvements. There are several current research efforts that address the modeling and assessment approaches under the auspices of NCHRP, and other agencies, which will plug some key gaps in modeling. On the other hand, agencies have begun collecting data related to resilience improvements including project investments that have been designed with future conditions into consideration while mitigating hazard impacts. Field data like this may need to be collected through longer periods spanning a given asset’s service and design life to determine the actual return on investments because of incorporating resilience into asset design, construction, and maintenance considerations.

The research team also acknowledges the proposed metrics of the Promoting Resilient Operations for Transformative, Efficient, and Cost-saving Transportation (PROTECT) Program Discretionary Program, which includes an initiative where Federal Highway Administration (FHWA) collects resilience metric data on the projects it selects to monitor as part of the program. (Federal Highway Administration 2024). We think that this will provide some benchmarking and provide monitoring standards for data collected for resilience projects.

Importantly, NCHRP Project 23-26 also incorporates considerations for community resilience throughout NCHRP Research Report 1159 and highlights points along which users can be considered, providing sources of data, methods, and examples of manner of incorporation. Gaps and limitations to understanding and addressing community resilience have also been highlighted in the chapter, “Gaps and Future Research”, illustrating the level of work still required in this area.

All in all, this research is a key step in fulfilling the objectives of developing a performance-based planning, management, and investment approach in transportation resilience. The inputs enable consistent, standardized, and objective measures that provide the much-needed decision-support to justify initiatives and investments, transportation practitioners can continue to make the case for investing towards a sustainable, durable, and resilient transportation system.