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Support for Impacts of Climate Change and Variability on Transportation Systems and Infrastructure: Gulf Coast Study Phase 2 developed methodologies for evaluating vulnerability and adaptation measures for local transportation systems. These transferrable methodologies were pilot tested in Mobile, Alabama. The project team evaluated the impacts on six transportation modes (highways, ports, airports, rail, transit, and pipelines) from projected changes in temperature and precipitation, sea level rise, and the surges and winds associated with more intense storms.
The first task of this project involved conducting a criticality assessment of Mobile's transportation system. The large number of transportation assets made it infeasible to evaluate the vulnerability of all assets; nor was an evaluation of every asset necessary to develop an understanding of system-level vulnerabilities. Therefore, a criticality assessment was performed to identify which assets are most critical to Mobile. These assets were the focus of later steps of the study.
Define "criticality." Defining criticality is an exercise that depends on many factors, including local priorities based on the characteristics that the stakeholders value, data availability, and even the definition of each "asset". Evaluation criteria were developed for the following categories:
Table 1 lists a few example criteria developed for each mode.
Socioeconomic |
Use/Operational |
Health/Safety |
|
---|---|---|---|
Highways |
|
|
|
Ports |
|
|
|
Airports |
|
|
|
Rail |
|
|
|
Transit |
|
|
|
Pipelines |
|
|
|
Score and rank assets. Each asset's criticality was evaluated by scoring the criteria using statistics on use (e.g., volume of cargo throughput at a port); traffic modeling (to determine impact on the system if a particular segment were to become inaccessible); expert judgment; and other metrics. Each asset was given an overall criticality score of High, Medium, or Low,
The criticality assessment resulted in the following findings:
# of Total Assets |
# of Critical Assets |
|
---|---|---|
Highways |
630 bridges 644 miles |
Bridges: 71 bridges Miles: 152 miles |
Ports |
61 ports |
23 ports |
Airports |
17 airports |
2 airport |
Rail |
14 facilities 590 rail miles |
7 facilities 347 rail miles |
Transit |
2 facilities 75 buses, vans, and maintenance vehicles |
3 elements |
Pipelines |
652 miles |
426 miles |
Rigid adherence to a scoring system could leave out areas of local or cultural importance that might not otherwise score highly against the other criteria. There may be locations that provide a difficult-to-quantify benefit. In Mobile, the city of Bayou la Batre scored low in multiple criteria, but in meetings with local stakeholders, the project team learned the importance of this community to the local fishing industry and Mobile's identity; the criticality of assets in this area was subsequently revisited. This example also highlights the importance of vetting the results of the quantitative analysis with a variety of stakeholders to ensure that essential assets are being captured.
It may be appropriate to identify characteristics that automatically confer a high criticality score. In this study, all criteria were weighted equally. However, future analyses could consider characteristics, such as role in emergency evacuation plans, to be automatic qualifiers for a designation of highly critical.
A criticality assessment is not an assessment of vulnerability. If an asset is considered to not be highly critical, it will not be evaluated for vulnerability, but this does not mean that it isn't vulnerable.
There are two key resources available for conducting transportation criticality assessments:
Resources:
Gulf Coast Study: http://www.fhwa.dot.gov/environment/climate_change/adaptation/ongoing_and_current_research/gulf_coast_study/
Contacts:
Robert Hyman
Sustainable Transport and Climate Change Team
Federal Highway Administration
robert.hyman@dot.gov, 202-366-5843
Robert Kafalenos
Sustainable Transport and Climate Change Team
Federal Highway Administration
robert.kafalenos@dot.gov, 202-366-2079
Brian Beucler
Hydraulics and Geotechnical Engineering Team
Federal Highway Administration
brian.beucler@dot.gov, 202-366-459
Figure 1: Rail asset in the study area. Photo credit: Emmett Tullos III, http://www.flickr.com/photos/emmett_ns_tullos/2281137196/
Figure 2: Highway asset in the study area. Photo credit: Infrogmation, http://www.flickr.com/photos/infrogmation/4723933893/
Figure 3: Transit asset in the study area. Photo credit: Wave Transit System, used with permission
Figure 4: Map of the location of various community facilities such as schools, colleges and universities, emergency service locations, government institutions, and health care facilities in the study area
[1] Available at http://www.fhwa.dot.gov/environment/climate_change/adaptation/ongoing_and_current_research/gulf_coast_study/
[2] Available at http://www.fhwa.dot.gov/environment/climate_change/adaptation/publications/assessing_criticality/