The Federal Highway Administration (FHWA) Office of Planning, Environment and Realty's (HEP) Surface Transportation Environment and Planning Cooperative Research Program (STEP) ended on September 30, 2012. For current HEP research information, please see HEP's research web site.
Assessing Vulnerability and Risk of Climate Change Effects on Transportation Infrastructure: Pilot of the Conceptual Model
This flowchart illustrates the structure of the Risk Assessment Model. Throughout the flowchart, orange boxes indicate that the step is outside the scope of the Risk Assessment pilot, while green boxes indicate that the step is inside the scope. Light green boxes indicate one of three primary components of the Risk Assessment model, and they contain two or more dark green boxes that represent specific steps of the Risk Assessment model.
The conceptual model consists of three primary components: inventory of assets, climate information, and risk to assets and the transportation system. The first two components can be considered simultaneously, and aim to identify (a) which assets are important to the transportation system, and (b) which climate variables are likely to occur, and/or which variables could experience a high-magnitude change. The third component combines the results of the first two to assess how climate changes could impact each important asset, and how significant those impacts could be.
At the top left of the diagram is the first component, "Inventory of Assets," which contains two dark green boxes. A short arrow connects the top box, "Develop inventory of assets," to the "How important is each asset?" box below. Because the in-scope activities under this component will rely on existing resources developed outside of the scope of this Risk Assessment model, there are two orange boxes entitled, "Existing inventories" and "Existing priorities, evaluation tools" that feed into this component. Altogether, this component diagram indicates that transportation agencies should draw from existing inventories to develop their own inventory of assets they are concerned with, and then to use existing priorities and tools to assess the importance of each one of those assets. If the asset is judged to be less important, an arrow leads to an orange box that reads "Monitor and revisit as resources allow." If the asset is judged to be more important, an arrow leads to the third component of the diagram, labeled "Risk." This third component of the diagram will be described later.
At the top right of the Risk Assessment Model is the second component, a light green box named "Climate Information." Within this component are two dark green boxes. The top one reads, "Gather climate information (observed and projections)." The bottom dark green box reads, "What is the likelihood and magnitude of future climate changes?" Transportation agencies should consider these questions with the help of existing data sets, as indicated by the orange box called "Existing data sets" that feeds into the "Climate Information" component. The diagram presents two possible options for Climate Information component. If both the likelihood and magnitude of the effect is judged to be low, then the recommendation is to monitor and revisit as resources allow, as indicated by the arrow pointing to the orange "Monitor and revisit as resources allow" box. However, if either the likelihood or the magnitude is expected to be high, an arrow points to the light green "Risk" box, the third and final component of this Risk Assessment Model.
The Risk component contains four dark green boxes. The first one reads, "Is the asset vulnerable to projected climate effects?" If the asset is judged to have low vulnerability, an arrow leads to the orange "Monitor and revisit as resources allow" box. If the asset is judged to have medium or high vulnerability, the flowchart points to two additional questions simultaneously in side-by-side dark green boxes. The left question reads, "What is the likelihood that future stressors will measurably impact the asset?" The right question reads, "What is the consequence of the impact on the asset?" Arrows from those two questions point to a third question in a dark green box below the other two which reads, "What is the integrated risk?" If the integrated risk is low, then the next step is to "Monitor and revisit as resources allow", which is represented in an orange box. If the risk is high or medium, an arrow leads to an orange box that reads, "Identify, analyze, and prioritize adaptation options."