and flexible approach to the federal permitting process can allow state and local agencies to align their efforts. B Funding, performance, and accountability. The final category of policy options revolves around funding, performance, and accountability. These policy options range from assessing the long-term costs and benefits of adaptation measures to developing performance measures to determining how to prioritize and fund adaptation projects. The funding mechanisms at the federal and state level can provide incentives for addressing climate change impacts through proactive adaptation planning.
2.5 Summary of Key Findings from Existing Studies The literature reviewed for this paper suggests that potentially the greatest impact of climate change for North America’s transportation systems will be flooding of coastal roads, railways, transit systems, and runways because of global rising sea levels, coupled with extreme storm events and storm surges, and exacerbated in some locations by land subsidence. Flooding also will be a concern in non-coastal areas due to an increase in heavy precipitation events. Other impacts include extreme hot days and heat waves. Finally, the Arctic transportation systems face a unique set of concerns related to climate change, including the thawing of permafrost foundations under infrastructure, shorter seasons for ice roads, and significant ecological changes. One of the important findings of the literature is the need to develop a process for identifying assets and locations that are vulnerable to climate change. The process should use specific local information and knowledge, and incorporate region-specific climate change forecasts and scenarios. The process also would make use of geospatial techniques to better analyze the spatial relationships among topography, development,
and climate. Identifying and prioritizing vulnerable assets is critical to determine which assets require adaptation; identifying vulnerable locations is important to enable communities to proactively minimize future risks. A fundamental conclusion drawn from the literature is that sound adaptation planning is grounded in a risk-assessment approach. To take effective action, it is essential to understand where transportation services are vulnerable — particularly the most critical points in the system — and how that vulnerability will change over time. This risk can then be assessed alongside other risks to decide what action is appropriate: Is an engineering intervention required immediately? Can intervention wait for the relevant point in the maintenance or reconstruction cycle? Is another management or policy response needed? There is a critical need to develop and refine risk-assessment and management approaches that meet the needs of transportation decision-makers. One approach that has relevance to climate adaptation and risk analysis is the experience on earthquake retrofitting for bridges. Following the 1994 Northridge earthquake in California, the U.S. Congress passed legislation allowing the use of Federal Highway Bridge Replacement and Rehabilitation Program (HBRR) funds for the seismic retrofit of nondeficient bridges (as defined by the National Bridge Inspection Standards). The seismic retrofit program in California has evolved into a highly sophisticated system. The screening program that began in the early 1990s incorporates a risk algorithm that evaluates the major factors that affect seismic performance, such as structural details, earthquake fault proximity, soil conditions, etc., as well as factors for hazard and risk. While assessing risk due to climate factors is more complex, the experience in assessing seismic risk may help inform the development of approaches to the climate risk assessment challenge.
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