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1Â Â The nation is facing risks from aging and deteriorating transportation infrastructure. Manag- ing this infrastructure and providing a safe and efficient transportation network is a top priority for transportation agencies. State transportation agencies, therefore, must manage numerous risks to the many assets under their purview. This report advances the risk management state of the practice by demonstrating several tools and techniques for assessing risks to the condition and performance of transportation assets. Title 23 Part 515 in the U.S. Code of Federal Regulations requires state departments of trans- portation (state DOTs) to develop risk-based transportation asset management plans (TAMPs) that incorporate a risk management plan. With regulations now in place and transportation agencies beginning to focus on formal asset risk management, tools and techniques to support managing risks to transportation assets have become more important. Before this report, pre pared for NCHRP Project 08-118, âRisk Assessment Techniques for Transportation Asset Management,â most asset management risk publications focused on what could be called âqualitativeâ risk management, that is, the identification and assessment of risks largely by eliciting opinions from subject matter experts (SMEs). NCHRP 08-118 focused on techniques and tools agencies can use to augment their decision- making processes related to managing risks to assets. The research team reviewed U.S. and inter- national research on asset risk management practices and surveyed state transportation agencies to identify the state of the practice for enterprise-, network-, and program-level risk manage- ment. These efforts helped the research team identify gaps and constraints that prevent transpor- tation agencies from implementing strategies and tools to address uncertainties at the national, state, and local levels. These gaps and constraints impact the achievement of asset performance goals for bridges, pavements, and other infrastructure assets. The research team then selected the high-priority gaps and constraints and selected easy-to-use tools and techniques to address them. The team selected 12 in five major categories for further study and developed methodologies to implement each. Where possible, simple off-the-shelf tools, such as Excel spreadsheets commonly available to transportation agencies, were used to imple- ment the techniques. In other studies, bridge and pavement management systems, also common in transportation agencies, were used. All 12 studies were developed with enough detail to enable transportation agencies to follow the steps included in the study and implement them. Each consisted of seven major steps, referred to as protocols, described in both this report and the appendices to this report. These protocols clearly state the objective of the study, then describe the tools and techniques, the methodology followed, and the steps to use when implementing it. The report discusses the input data, any configuration of tools needed, and the output results. It discusses the agency SMEs to be engaged, S E C T I O N 1 Overview of the Research
2 Risk Assessment Techniques for Transportation Asset Management: Conduct of Research the difficulty or ease of implementation, the resources needed, and how the results can be used to support risk-based asset decisions in an agency. The protocols were intended to help agencies identify the techniques and tools that best fit their specific asset risk needs. Nearly all the studies used data available from transportation agencies. Seven of these studies were then pilot tested in transportation agencies. However, the necessary detailed steps are described for all the studies, whether piloted or not, so that transportation agencies can follow them in their implementation efforts. Three studies within this report demonstrate how simple, inexpensive off-the-shelf tools and techniques can enhance the measurement of risks related to managing assets. Six studies dem- onstrate how to quantify risks using bridge and pavement management systems. Such capabilities are inherent within commercial bridge and pavement management systems, but at the time of this report, few DOTs were using them. Two of the tools were selected to demonstrate how to better link the risk management processes seen in TAMPs with the tools for assessing climatic and extreme weather risks. This report includes a crosswalk and decision tree to help risk managers and resilience analysts âspeak the same languageâ to manage climate risks. Another study demonstrates how risk management can be more closely integrated into all asset management processes. This report uses the framework of the 23 CFR 515 asset management plans to demonstrate how risk can be considered in almost every step of the asset management process. The 12 studies included in this report are described in the following: â¢ Studies 1 and 2 demonstrate how to quantify and communicate uncertainty around financial plans. These two studies demonstrate how off-the-shelf risk tools can help quantify the uncer- tainty and variability around asset management financial plans. State transportation agencies are required to prepare financial plans for their 10-year TAMPs that specify 10-year forecasts of revenues, investments by work type, and the resulting bridge and pavement conditions. Studies 1 and 2 illustrate how off-the-shelf deterministic and probabilistic forecasting tools can help quantify and help communicate the uncertainty around the forecasts contained in these plans. â¢ Study 3 demonstrates how to develop a bridge utility index. This study shows how a bridge management system (BMS) can calculate a risk index by generating a risk utility function. Agencies can use the utility function to analyze and inform mitigation decisions with the BMS. â¢ Study 4 demonstrates how to create a pavement section flooding risk index. This study shows how a pavement management system (PMS) can be used to calculate and analyze a risk index that incorporates a pavement sectionâs risk of flooding due to storm events, sea level rise, high tides, or storm surge. This study also includes the risk index in the PMS analysis to determine the benefit of selecting projects that mitigate risk. â¢ Study 5 demonstrates how to create a non-NBIS culvert risk index. This study illustrates a methodology for modeling risk on drainage structures not covered by the National Bridge Inspection Standards (NBIS). This study was conducted at the asset level and illustrates the methodology for defining an asset-level risk index for use in a DOTâs PMS. â¢ Study 6 demonstrates how to create a landslide hazard management risk index. This study presents a proof-of-concept methodology to create a risk-based index for managing the vul- nerability of roadway slopes to failures of various types using existing pavement or general asset management systems that are in use by most DOTs. â¢ Study 7 demonstrates pavement network risk analysis. This study demonstrates a method for assessing risk at the network level using a PMS. This analysis included the identification of high, expected, and low values for various inputs in the definition of scenarios being tested. This process was developed for implementation in any configurable PMS for which similar inputs can be defined when users create and analyze network-level optimization scenarios.
Overview of the Research 3Â Â The variables assessed were inflation rates and available funding levels to demonstrate the risks those variables generate. â¢ Study 8 demonstrates bridge network risk analysis. This study presents a framework for evaluating funding risk at the network or program level. Example data from a bridge pro- gram were used to illustrate the framework. The report includes the definition of the scenario being tested and details the identification of the scenario inputs. A DOT could implement the process identified in this study in any configurable BMS. The variables tested were differing funding levels. â¢ Study 9 presents a crosswalk between climate change vulnerability and risk terminologies. This study includes detailed, user-friendly guidance on how to use the information collected in a typical climate change vulnerability assessment and correlate it to the typical TAMP risk terminology. It also includes a customizable rubric to serve as a starting point for assessing the likelihood of climate risks. With the rubric, agencies could scale up or down or modify the time frame of analysis as needed. â¢ Study 10 presents a decision tree for selecting climate risk management strategies. This study developed an example decision tree for how to move from risk assessment to risk man- agement. The example used rising temperature risks to pavements as an example assetâhazard combination. â¢ Study 11 demonstrates how to institutionalize risk management into asset management plans. This study illustrates how to incorporate risk management into every section of a trans- portation asset management plan. Because each TAMP section reflects an asset management process, the result is to ingrain risk considerations into major asset management functions. â¢ Study 12 demonstrates how to use a probabilistic decision tree to evaluate risk. This study illustrates how an agency can evaluate the uncertain costs and benefits around a major asset management decision. The decision tree enumerates the potential savings and potential losses from developing a statewide chip seal program when costs, savings, and success are uncertain. Summaries of each studyâs key takeaways and benefits are provided along with next steps for successful implementation. In addition to the 12 studies, this report includes a summary of the risk management primer and a summary of the state of the practice. The primer summarizes statistical concepts that support the quantification of risk. When risks are quantified, then trade- offs can be calculated. The primer explains how risk can be measured as a utility that can be compared with other utilities, such as the value of an asset in good condition. The state of the practice summary includes a broad review of risk management practices DOTs use in the United States and across the English-speaking world. Report appendices are published as NCHRP Web-Only Document 366: Risk Assessment Tech- niques for Transportation Asset Management: Appendices, available on the National Academies Press website (nap.nationalacademies.org). These appendices contain a literature review, the detailed state of the practice report, and additional detail on the protocols of the studies that were not piloted.