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Assessing Criticality in Transportation Adaptation Planning

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Hurricane evacuation routes (green arrows) in south of Cape Canaveral, Florida. Map courtesy of Brevard County Emergency Management Office.

May 25, 2014

Prepared for

USDOT Center for Climate Change and Environmental Forecasting under The Gulf Coast Study, Phase 2: Impacts of Climate Change and Variability on Transportation Systems and Infrastructure

Managed by the Federal Highway Administration (FHWA) Office of Planning, Environment, and Realty

Prepared by

ICF International

Introduction

Before initiating a climate change vulnerability assessment, transportation agencies need to decide which assets they wish to evaluate. Identifying the relevant assets for a vulnerability study and determining which characteristics of these assets to examine can help agencies narrow the scope of the study, making it more manageable and affordable while allowing more in-depth assessment of the selected group of assets.

One way to narrow the range of assets to be evaluated is to conduct a criticality assessment, which involves identifying the most critical elements of the transportation system for analysis, using quantitative or qualitative criteria. A criticality assessment provides a structured way to focus on assets that are most important for the functioning of the transportation system.

This memorandum discusses common challenges associated with assessing criticality, options for defining criticality and identifying scope, and the process of applying criteria and ranking assets. It uses examples from the FHWA pilots and the Gulf Coast 2 study (see text box above) to illustrate a variety of approaches that have been used for assessing criticality. The Appendix lists criticality criteria developed under the Gulf Coast Study, Phase 2, along with brief explanations for why each criterion was chosen.

Common Challenges in Assessing Criticality

The following challenges are common when attempting to identify critical assets:

• Definitions of criticality are vague and can be difficult to implement. Who decides what is critical? Definitions of "criticality" depend on the lens through which they are being evaluated (e.g., public health, emergency response, economic growth, mobility).
• Determining what constitutes "an asset" is not always straightforward. Organizations must decide whether (and how) to include critical services that support transportation goals (e.g., Intelligent Transportation Systems, telecommunications, power) and the appropriate level of disaggregation. For example, should the asset be defined as the airport complex, the access road from the airport to another destination (e.g., the city center), a specific runway, or the pavement on the runway?
• It is difficult to define the boundaries and relationships of the system(s) in which the asset is embedded (e.g., a highway segment may have more economic importance to a multi-state region than to the county where it is located).
• It can be time-consuming and difficult to gather certain types of data on assets in a study area, particularly privately-owned assets (e.g., pipelines, port facilities, freight rail).
• Even when data are readily accessible from internal databases or elsewhere, it can be very difficult to integrate information on assets efficiently (e.g., spatial data may have incorrect or inconsistent reference information, making integration with other spatial data challenging).

Options for Defining Criticality and Limiting Study Scope

This section discusses how the goals and audiences for a vulnerability study may shape criteria used to assess criticality, along with key considerations in defining criticality and the scope of a vulnerability assessment.

Goals and Audience for Vulnerability Information

Traditionally, assessments of criticality may connote notions of risk, but critical assets in the context of a climate change vulnerability assessment are intended to include those assets of "greatest importance," such as assets that are of economic importance, provide access to healthcare facilities, serve as emergency evacuation routes, provide social connectivity, have cultural significance, or support other core values.

The extent to which each of these elements is included in a criticality assessment should reflect the goals of the decision-makers who will ultimately use the results and recommendations of the vulnerability assessment. For this reason, it is necessary to clearly define the purpose and intended audience for the overall vulnerability assessment.

For example, the analysis may be intended to communicate the risks of climate change, justify specific projects, inform design decisions on projects in the pipeline, or a host of other outcomes. The intended use of vulnerability information and the intended audience should drive the design and approach of the criticality assessment.

Table 1 uses four hypothetical studies with different goals to show how factors such as target audience and purpose might shape the study scope and details of a criticality assessment.

Table 1: The Influence of Study Purposes, Audiences, and Outcomes on Criticality Criteria

There is no single right way to assess criticality as the first step in an overall vulnerability assessment. Key questions to consider in developing a criticality assessment include:

• Should your assessment include many assets or only a few? (Is the intent to go deeply into a few key assets or to focus broadly, but with less depth?)
• Should your assessment include a range of transportation modes, or only one mode?
• How should you define "critical?" Should the focus be on economic drivers, health and safety concerns, replacement cost, or other criteria?
• Who are your stakeholders? Might the criticality assessment be leveraged for other uses; might there be an existing criticality assessment that could be adapted for this purpose? When should you involve stakeholders in the process?

Defining Criticality

Before an asset's degree of criticality can be determined, the term "criticality" itself must be clearly defined in the context of the vulnerability assessment. For many agencies, a critical asset is defined as an asset that is so important to the study area that its removal would result in significant losses.[1] However, this definition does not resolve three important questions: what is an asset, what is the study area, and who defines significant losses?

If we assume that our definition of "critical" should align with the profile of our target audience, we can make the definition of criticality more specific. For example, municipal and county decision makers are likely to care about high-profile, high-use assets across all modes, while senior management within a single agency may be more likely to prioritize assets that the agency owns or operates.

Prior work on identifying critical infrastructure has focused mainly on major transportation facilities that serve a national purpose-primarily interstate travel and trade. However, assessing what is critical to a local area requires that other criteria be taken into consideration, such as those related to community and economic viability. Recognizing interstate travel as the sole criterion for asset criticality might not capture the full measure of important transportation assets that support the economy of a particular area. It may be necessary to acknowledge the importance to the community of regional and local transportation connections (including major port facilities and railroad operations).

Defining Criticality in the Gulf Coast Study

Stakeholder input can be vital to defining criticality in a region, as was the case in the Gulf Coast Study. During the project vulnerability assessment process, various local and regional stakeholders were engaged to help define "critical" for the purpose of the study. The determination of criticality of transportation assets in Mobile was based on the following categories of criteria:

• Socioeconomic importance
• Use/operational importance
• Health and safety importance

The socioeconomic importance of an asset relates to how it contributes to the social viability of the community, as well as its role in supporting the local economy. Social viability involves measuring the importance of transportation assets to the community in terms of providing access to facilities that allow the community to function, while economic viability involves an asset's role in supporting commerce and providing access to major employment destinations. Many individual components, including households, schools, libraries, government centers, employment centers, retail establishments, places of worship, and other locations define a community as a whole. The role of transportation in providing connectivity between those destinations is well defined and enables community viability and livability. Connections to these facilities were factored into the Gulf Coast Study criticality analysis in recognition of their importance to community and economic functioning.

Operational importance was assessed by considering the use of each link in the transportation network, its capacity, and the importance of the operations that the asset supports to the Mobile County economy. Examples of use measures include average daily traffic along roadways, ridership for transit, annual gross tonnage for rail lines, and cargo volumes for ports.

Health and safety considerations include the asset's role in evacuation plans, disaster relief and recovery plans, the asset's role in moving hazardous materials, inclusion in the national defense system, and the extent to which an asset provides access to health care facilities.

Because of the far-reaching goals of the study, the assessment of critical assets for Gulf Coast Phase 2 covered all modes (U.S. DOT, 2011). However, the assessment was also governed by the types of assets present in Mobile, Alabama: for example, transit in Mobile is currently a bus-only service, so only criteria relevant to those services were included. The emphasis on replicability and transferrable lessons drove the study team to focus the initial assessment on transparent, quantitative (wherever possible) criteria; these criteria were then equally weighted to reflect socioeconomic importance, operational/use, and health and safety concerns. Because Mobile is centrally located among multiple regional intermodal connections, accessibility to the ports and pipelines was also factored into criticality.Assessing Infrastructure for Criticality in Mobile, Alabama (link)

Defining scope

Defining the scope of a vulnerability assessment includes determining how many critical assets to identify and how to draw the spatial (e.g., county, state), temporal (e.g., existing, planned, existing and planned assets), modal (e.g., highways, ports, freight rail, transit), ownership (e.g., state-owned, county-owned, privately owned), and other parameters of the study. The scope of a vulnerability analysis should reflect the objectives and constraints of the target decision makers and key stakeholders. The sections below provide a discussion of several kinds of boundaries and the types of considerations that may go into decisions regarding them.

Geographic scope

Geographic scope may be defined by the boundaries of an agency's jurisdiction, or may need to be defined through working with relevant partners to determine the area of consideration. For state and local transportation agencies, jurisdictional boundaries will be one of the most important determinants of scope. For metropolitan areas-such as Newark, New Jersey, where the area under the MPO's jurisdiction acts as an integral part of significant transportation-related activities in the Northeast corridor-the importance of a particular asset may need to be considered in two contexts: the importance of the asset to parties involved in the vulnerability assessment, and the importance of the asset in the context of broader regional or national systems that include the asset (in the case of Newark, for example, this could include interstate commerce on I-95).

Temporal scope (Future Assets)

The study goals and audience may drive the temporal scope of the assets being assessed for criticality. For example, if the vulnerability assessment is oriented toward short-term changes and how to manage for them, the criticality assessment should focus on existing assets. Alternatively, if the goal of the assessment is to help an MPO consider climate change effects in its long-term planning efforts, it may be useful to include the assets in the long-range transportation plan in the "universe" of assets to be screened against criticality criteria and ultimately reviewed for vulnerability. If the audience for the study has a purview for assets with long design lives (and planned upgrades), or assets envisioned for the future, it is important to include these assets in the analysis.

Modal Scope

The position of the decision maker and the perspectives of the stakeholders should determine the initial list of modes to include in the analysis. In many cases, the study may include only modes that the target decision maker or ultimate audience can control or influence. Highways, public transit, aviation, maritime, pipelines, bicycle and pedestrian facilities, and railroads are all examples of modes that could potentially be included in the analysis.

Example criticality criteria for different modes that were used in the Gulf Coast study are provided in the Appendix.

Ownership

The agency assessing criticality may want to limit the scope of assets considered in the criticality assessment based on ownership of the assets. Smaller, more focused analyses may limit the scope to assets owned and/or operated by the agency itself. For example, the Washington State DOT pilot focused its analysis on the State Highway System assets since the agency is responsible for the planning, design, construction, and maintenance of this system. That system includes assets such as roads, wetland mitigation sites, stormwater treatment facilities, rest areas, park and ride lots, transit facilities, maintenance facilities, air field assets, and the Washington State Ferry system.

Applying Criteria and Ranking Assets

After articulating the project's scope, purpose, and intended audience, the next step is to assess the criticality of assets.

Defining Assets and Systems

The criticality of an asset depends both on its physical characteristics (e.g., replacement value) and on its function in multiple systems (e.g., emergency evacuation route, key commercial route, level of activity, value of freight carried). One of the challenges that agencies face during the criticality assessment is defining assets and determining which auxiliary systems to include in the analysis. For example, an agency undertaking a study aimed at educating the general public or local decision makers might prefer to aggregate assets into recognizable groups, such as bridges, highways, and culverts. A study aimed at increasing agency cooperation will need a higher level of detail, with a particular focus on asset function across systems. Finally, a study with the objective of implementing adaptation strategies (e.g., asset management systems considering changes to design/retrofits) will require a level of detail high enough to inform quantitative assessments of vulnerability and risk and analyses of possible adaptation strategies specific to that asset.

Along with asset definitions, the study should define which supporting systems to include. Electricity transmission and distribution systems and intelligent transportation systems (ITS) are examples of auxiliary systems that might be considered "critical." The extent to which these systems are included in the criticality assessment depends on the purpose and intended audience of the study. If emergency management is a primary or secondary goal, the agency may want to include ITS systems. If power outages are a primary concern, the vulnerability assessment may need to address electricity assets.

Three Approaches to Criticality Assessment

In practice, the FHWA pilot projects have generally used three approaches to narrow the universe of transportation assets based on their individual interpretation of criticality: the desk review approach, the stakeholder solicitation approach, and the hybrid approach. Each of these approaches is described in more detail below.

Approach 1: Desk Review

One approach to formulating criticality criteria is to identify a broad range of criteria that capture use and access across a range of modes and systems. The desk review emphasizes objectivity, and uses quantitative information that is based on readily available data sources and requires little local knowledge to apply in asset ranking. In the desk review approach, modal experts or modelers use prioritization schemes already in place and rank assets based on data such as average daily traffic, functional classification, and expert judgment. This approach may or may not weight individual factors in an attempt to rank and classify the assets. This method may lend itself to studies intended to further research on appropriate decision support tools in this area, and/or studies for academic audiences. It may also be used as a first step in the process of identifying critical assets, as discussed below under Approach 3. Advantages of the desk review approach include its transparency and replicability. A potential disadvantage is that data may be lacking on important elements of criticality, many of which are qualitative and locally specific.

Examples:

VDOT/Hampton Roads Pilot Approach

The Virginia Department of Transportation (VDOT) led this pilot in partnership with the University of Virginia, the Hampton Roads Planning District Commission, and Hampton Roads Transportation Planning Organization. The pilot project team used multi-criteria decision analysis to evaluate transportation priorities in the region. To identify critical assets, VDOT compiled an initial selection of over 1,000 existing transportation assets from its asset management system. To narrow the scope, the project team screened for high-risk assets using criteria that included traffic volume, elevation relative to mean sea level, location on a maintenance priority route, and location on a hurricane evacuation route. The narrowed selection consisted of about 30 major assets, including two traffic management centers and three bridges.

New Jersey Pilot Approach

The North Jersey Transportation Planning Authority (NJTPA) led the interagency NJ Partnership to assess the vulnerability of transportation systems in New Jersey. Much of the state's infrastructure is aging and concentrated near major rivers and the coast. The NJ Partnership wanted to understand how to make more strategic capital investments in light of the changing climate. To accomplish this goal, the project team conducted a climate vulnerability assessment on transportation assets in two geographic areas of focus. As a first step in this assessment, the team assigned assets into tiers of criticality based on the extent to which each asset connects critical destinations. The following factors determined criticality:

• Importance of the destinations, identified based on jobs and population density
• Magnitude of the connections, identified by traffic volume or ridership
• Emergency function of routes, identified by presence of coastal evacuation routes and other factors

Using a Geographic Information System (GIS)-based tool, the project team scored assets according to these criteria and then grouped them into three tiers of criticality: "low and medium," "high," and "extreme."

Approach 2: Stakeholder Elicitation

Determining asset criticality based on input from selected stakeholders and local experts is a second approach to assessing criticality. With a stakeholder elicitation approach, the project leaders will identify a group of stakeholders in the region with expert knowledge of specific interests (e.g., commercial activity, public safety, or road maintenance). The project leaders will then organize a workshop or series of workshops with these stakeholders to elicit feedback on which assets are critical.

Advantages of the stakeholder approach include getting buy-in from relevant stakeholders early in the vulnerability assessment process, encouraging collaboration and communication among stakeholders and actors likely to implement any adaptation strategies, accessing information that is not readily available in publicly available datasets, and quickly assessing criticality without a lengthy research process. However, the results of a stakeholder-driven process are highly subjective. The outcomes depend strongly on the quality of the workshop facilitation, the composition of workshop attendees, and the participation of key experts.

Examples:

The Oahu MPO Pilot Approach

The Oahu MPO pilot held a workshop that brought together climate scientists and local planning, engineering, and management professionals. Workshop participants identified and prioritized vulnerable transportation asset groups through an iterative discussion that relied heavily on local knowledge. A series of facilitated discussions helped participants evaluate the economic and social consequences of asset failure to due climate change. Based on the consensus from these discussions, the participants identified a small number of highly critical assets:

• Honolulu Harbor area
• Honolulu International Airport area
• Kalaeloa Airport, Kalaeloa Barbers Point Harbor, and Campbell Industrial Park
• Three bridges in Waikiki
• Rt‐93, Farrington Highway

The project team then used GIS to map critical transportation infrastructure and associated access routes in each asset area.

WSDOT Approach

The objective of the Washington State Department of Transportation (WSDOT) pilot study was to develop a methodology for evaluating transportation assets vulnerable to climate change-related impacts and to prioritize those assets for proactive response actions. The pilot focused only on the assets it owns and operates, including airports, ferry terminals and operations, rail lines, state routes and interstate roadways, bridges, culverts, ramps, adjacent pedestrian and shared-use paths, roadsides and migration sites, and WSDOT-owned buildings. WSDOT involved O&M and engineering stakeholders in various facilitated workshops across the state in assessing criticality. The project team used a 1 to 10 rating scale to articulate the relative criticality for each asset. Workshop participants scored criticality based on the asset's character, its general function, and use (see Figure 1).

Figure 1: Rating Scale for Asset Criticality used by WSDOT

Approach 3: Hybrid Approach

The hybrid approach includes aspects of both the desk review and the stakeholder elicitation approaches. Hybrid approaches often begin the process with a desk review, which identifies a long list of critical assets based on commonly available data such as average daily traffic or economic information for the region (e.g., data on imports/exports from a particular port). The project team will then use the results of the desk review to inform and structure feedback from stakeholders and local experts.

Examples:

San Francisco/MTC Pilot Approach

San Francisco's Metropolitan Transportation Commission partnered with several other organizations on a pilot to assess climate vulnerability and risk in Alameda County, California. The project team focused on four categories of transportation infrastructure in Alameda: road network; transit network; storage, operations and maintenance, and control facilities; and bicycle and pedestrian networks.

The project team applied three filters to narrow down the asset inventory to a small set of representative assets. The first filter spatially selected for the assets located within the end-of-century sea level rise inundation area, discarding assets less likely to be exposed to sea level rise. The second filter analyzed the environmental, economic, and equity characteristics associated with each asset. In most cases, applying these two filters limited the list of representative assets to three or fewer within each of the four asset categories. The exception was the road network category; since there were hundreds of discrete arterial, collector, and local streets, the project team hosted a workshop to identify priority assets for evaluation. Participants in the workshop voted for priority transportation assets within Alameda County by affixing stickers to inundation maps.

Approach Used in the Gulf Coast Phase 2 Criticality Assessment

During the Gulf Coast Phase 2 project, criticality was defined as a function of socioeconomic considerations, use/operations, and health/safety priorities. Since the project looked across a number of modes, these overarching categories of criteria were chosen to maximize consistency across modes, although specific criteria in each category for the various modes were subsequently identified. The audience for this project includes transportation agencies across the country as well as decision makers in Mobile, Alabama; thus, objectivity, inclusivity, and transparency were key. This is why the Gulf Coast Phase 2 project used a hybrid approach with a strong desk review element augmented by periodic input from a local working group. The working group weighed in on the initial approach, the categories of criteria, and the mode-specific criteria. Transportation experts evaluated all available data and scored assets from 1 to 5 (low to high). Assets were then binned into high, medium, and low criticality categories based on the distribution of asset scores. The project team presented the results from this desk review at a stakeholder meeting and adjusted the list of critical assets based on stakeholder feedback. See the Appendix for the criteria used in the Gulf Coast Phase 2 project.

Assessing Infrastructure for Criticality in Mobile, Alabama (link)

Conclusions

There is no single right way to assess criticality as part of an overall vulnerability assessment; this exercise must be designed to suit the needs of the study and the ultimate users of the information to be provided on vulnerability. However, there are some common elements seen in the assessments discussed in this document. Based on these examples, successful criticality assessments generally:

• Identify assets that align with the priorities and values of the target audience.
• Create buy-in from important stakeholder groups (stakeholders who comprise or influence the target audience).
• Develop and organize relationships, contact information, data sources (spatial, financial, engineering), and other resources that will be useful during the subsequent vulnerability and risk analysis.
• Involve some sort of qualitative or quantitative ranking scheme based on identified criteria.

State DOTs, MPOs, and other transportation practitioners around the country have used a variety of criteria and methods to define criticality to meet the needs of their projects. The steps taken by these agencies can help inform future vulnerability assessments, and may assist other decision makers in taking the first step toward understanding how climate change impacts may affect transportation assets in their region.

Resources

Climate Change & Extreme Weather Vulnerability Assessment Framework: http://www.fhwa.dot.gov/environment/climate_change/adaptation/publications/vulnerability_assessment_framework/

FHWA Climate Change Resilience Pilots: http://www.fhwa.dot.gov/environment/climate_change/adaptation/resilience_pilots/index.cfm

Gulf Coast Study: http://www.fhwa.dot.gov/environment/climate_change/adaptation/ongoing_and_current_research/gulf_coast_study/index.cfm

Assessing Infrastructure for Criticality in Mobile, AL: http://www.fhwa.dot.gov/environment/climate_change/adaptation/ongoing_and_current_research/gulf_coast_study/phase2_task1/index.cfm

References

Department of Homeland Security (DHS). 2007. Transportation Systems: Critical Infrastructure and Key Resources Sector-Specific Plan as input to the National Infrastructure Protection Plan. Department of Homeland Security. Arlington, VA. http://www.dhs.gov/xlibrary/assets/nipp-ssp-transportation-systems-2010.pdf

U.S. Department of Transportation (DOT). 2011. Assessing Infrastructure for Criticality in Mobile, Alabama: Final Technical Memo, Task 1. Prepared by ICF International and PB Americas for the USDOT Center for Climate Change and Environmental Forecasting. Report No. FHWA-HEP-11-029. http://www.fhwa.dot.gov/environment/climate_change/adaptation/ongoing_and_current_research/gulf_coast_study/phase2_task1/index.cfm

Appendix

Continue to Appendix.

[1] For example, see DHS (2007). Transportation Systems: Critical Infrastructure and Key Resources Sector-Specific Plan as input to the National Infrastructure Protection Plan. Department of Homeland Security. Arlington, VA. <http://www.dhs.gov/xlibrary/assets/nipp-ssp-transportation-systems-2010.pdf>