Approaches for evaluating and implementing adaptation options have been rapidly evolving over the past few years and those at the vanguard have learned valuable lessons. Many transportation officials agree that they should consider climate change in their transportation processes, but still struggle with what concrete actions they should take and how to find and deploy the necessary resources. This section discusses some of the key challenges in implementing adaptation in the transportation sector and provides examples of strategies to overcome these barriers.
Resource constraints. Agencies are dealing with limited financial and human resources, including assets that are well beyond their anticipated useful life. A challenge to adaptation is the need to balance long-term resilience with more urgent requirements to meet acceptable levels of service. To achieve this, adaptation should not be considered a new and separate issue, but should be integrated into existing decision-making processes. Transportation officials can incorporate climate change considerations into the maintenance, upgrading, and expansion of assets as part of the asset management process. Emergency preparedness, post-disaster reconstruction, and long-range planning are additional venues to mainstream adaptation into decision making. Recognizing that there are multiple avenues for adaptation, FHWA released guidance on the eligibility of adaptation activities for funding under the Federal-aid and Federal Lands programs (FHWA 2012e). FHWA funds are applicable for adaptation across all stages, including the project planning, preventive maintenance, infrastructure preservation, and construction phases.
Another strategy is to implement adaptation as a co-benefit, rather than as an action in itself. For instance, Washington State DOT is installing bigger culverts to improve fish passage, which will also increase the system's capacity to handle future increased stream flows as a result of climate change (FHWA 2012b).
Regulatory or programmatic roadblocks to modifying guidelines and practices to mitigate risk. Some policies may not support or may even discourage rebuilding to projected conditions rather than historically observed conditions. Some examples of specific regulatory or programmatic issues include:
However, there has been recent regulatory development that can present opportunities to overcome these barriers. For example, while climate change is not currently a required consideration in transportation planning under Title 23 of the United States Code, in 2010, the Council on Environmental Quality issued draft guidance on addressing the effects of climate change under NEPA (Sutley 2010). If adaptation has to be considered as part of NEPA in the future, such guidance can help overcome the challenge of lack of political support.
At the local level, another programmatic barrier is the development of hazard mitigation planning separately from local planning processes. This leads to land use and transportation planning that inadvertently encourages development in risky areas. Communities are increasingly addressing this by incorporating hazard mitigation planning into local planning. For example, Chittenden County MPO in Vermont is working with the Department of Housing and Development to integrate climate change adaptation, hazard mitigation, and transportation into a single framework (FHWA 2012b). During FHWA's Midwest Transportation Adaptation Peer Exchange in 2011, participants agreed that county hazard mitigation plans provide a natural vehicle for climate change adaptation (FHWA 2012b).
Information availability and applicability to local decision making. The amount of projected climate data available can be overwhelming, making it difficult for transportation officials to determine which climate scenarios, models, and data to use for assessing vulnerability and adaptation options. Furthermore, climate projections are often not presented on the same scale as decisions are made, and it can be hard to translate projected regional climate changes into effects on specific transportation assets. State and federal resources can help overcome this barrier. Information on climate change projections and impacts is available from state climatologists or federal agencies including NOAA and the United States Global Change Research Program (USGCRP). FHWA has also published information on regional climate effects, focusing on transportation agencies (FHWA 2010).
State and federal policy drivers are another way of reducing this barrier. These high-level drivers are important both because they provide justification and impetus for incorporating adaptation into existing agency priorities, and because they help mobilize resources for resource-constrained local agencies. For example, Washington State has required all government agencies to use climate data from the University of Washington's Climate Impacts Group, thereby simplifying the process of selecting data sources. In California, Caltrans has issued "Guidance on Incorporating Sea Level Rise" (Caltrans 2011) to help internal staff working at the project and planning level determine whether and how to incorporate sea level rise concerns into their projects (FHWA 2012b).
A related barrier is that many transportation infrastructure engineering decisions are based on metrics such as peak flow, water volume and velocity, or intensity-frequency-duration curves for precipitation. These metrics would be affected by changes in rainfall patterns, but cannot be easily related to climate data about 24-hour precipitation. Determining how to translate climate model outputs into useful terms for engineers, particularly in the area of hydrology, is an ongoing area of research (Meyer et al. 2013).
Stakeholder engagement. Lack of coordination and information sharing among stakeholders can hinder the implementation of adaptation. If the public or target audience does not understand the importance of adaptation, they may be resistant to resources being spent on adaptation. It is therefore critical to engage stakeholders, both inside and outside the transportation agencies, in adaptation planning processes. Oregon and Washington DOTs, for example, started their vulnerability assessment by interviewing on-the-ground personnel. They also conducted workshops with internal staff to collect institutional knowledge as well as fostering ownership of the assessment results across the entire agencies. In addition, where there is difficulty in communicating the need for adaptation due to the politicized nature of the term "climate change", agencies have used other phrases such as "extreme events", "event management", "multi-hazard management", and "building resilience" (FHWA 2012b).
Interdependencies of transportation and other sectors (e.g., health and human services, power, telecom, disaster response). Transportation systems do not operate in isolation and some of the most critical impacts will most effectively be addressed by considering the interdependencies and engaging other sectors in developing solutions. As a result, transportation agencies need to work with other departments to develop holistic approaches for addressing vulnerability and building resilience. For example, North Carolina formed an Interagency Leadership Team in 2004 that includes 11 state and federal agencies to develop sustainable future transportation projects. These agencies were included as they are integrally involved in the state's transportation planning and development (NCILT 2013a). Since then, the Team has moved beyond transportation and led the effort to understand climate change vulnerability and analyze adaptation options across all sectors. It recently released a study entitled "Climate Ready North Carolina: Building a Resilient Future", which identifies potential climate change impacts and adaptation measures as well as examining strategies for multiple government agencies to work together in a coordinated adaptation framework (NCILT 2013b).