美國國家研究院(National Research Council)最新報告顯示，美國國內所有交通工具均將受到氣候暖化的影響，其中水災造成海平面上升、及強烈暴風雨所產生的大浪，對於沿岸地區一般道路、鐵路、交通運輸系統、機場跑道等的影響最為嚴重。
這份研究報告發現，5項氣候型態的轉變對於美國國內的交通影響甚鉅，例如炎熱天氣與熱浪的增加、北極圈溫度的攀升、海平面上升、降下豪雨與大雪機率的增加、以及颶風強度的增加等。
研究報告委員會做出結論，雖然氣候變遷的影響因地區而異，但可以確定的是，這些影響將會是廣泛的，人類與經濟活動將付出極大的代價；同時，必須及早對交通運輸系統的計畫、設計、建設、運作及維護等各個層面做出大幅調整。
Sverdrup/Jacobs Civil有限公司前董事長暨撰寫此份研究報告之委員會主席—史瓦茲二世(Henry Schwartz Jr.)表示，「對於交通運輸專家而言，該是正面迎向氣候變遷挑戰的時機了，同時將目前大部分的科學知識，藉由交通運輸系統的規劃，更可進一步體現。」
史瓦茲提出，「氣溫的上升，可能引起極端天氣或令人意想不到的天氣型態，例如北極海冰融化的速度比預期的迅速。而目前被視為疏散路徑的高速公路，間歇性水災的持續發生，可能與強烈颶風、豪雨產生連帶影響，進而阻斷高速公路的部分路段。」
委員會成員包括了來自麻州、紐約州、德州與加州的氣象學家、氣候科學家與相關策劃人員、以及運輸系統相關官員等，共同表示運輸系統的供應者須將焦點關注在疏散的規劃，同時與天氣預測機構、緊急應變措施制定機構進行密切合作。
史瓦茲補充，「目前預測次級大陸的大型區域之氣候變遷型態是可能的，較適於預測的區域範圍像是美國東部，可以適用於區域性的、或地區規模的交通基礎建設。」
美國交通運輸系統是依據當地天氣型態、天候狀況所設計並建造的，參考往年的溫度與降雨、降雪的紀錄進行預測；但研究報告發現，交通運輸系統規劃者與工程師使用的天候預測值，在天氣預測與極端氣候的狀況下可能已不再適用。
交通基礎建設的使用，若超出其原先所規劃，則可能緊繃並失去作用，以卡崔娜颶風(Hurricane Katrina)來襲後，紐奧良有90座橋樑遭摧毀可知。
委員會並指出，除了氣候變遷之外，仍有其他可能影響沿岸地區交通運輸系統的因素。像是沿岸地區人口的成長，預計將促進交通基礎建設的需求，同時人口數量與商業活動的增加，將有損毀道路的潛在可能。
Every mode of transportation in the United States will be affected as the climate warms, with the greatest impact expected to be flooding of roads, railways, transit systems, and airport runways in coastal areas because of rising sea levels and surges brought on by more intense storms, says a new report from the National Research Council.
The report identifies five climate changes of particular importance to U.S. transportation - increases in very hot days and heat waves; increases in Arctic temperatures; rising sea levels; increases in intense precipitation events; and increases in hurricane intensity.
Though the impacts of climate change will vary by region, it is certain they will be widespread and costly in human and economic terms, and will require major changes in the planning, design, construction, operation, and maintenance of transportation systems, the committee concludes.
"The time has come for transportation professionals to acknowledge and confront the challenges posed by climate change, and to incorporate the most current scientific knowledge into the planning of transportation systems," said Henry Schwartz Jr., past president and chairman of the engineering firm Sverdrup/Jacobs Civil Inc., and chair of the committee that wrote the report.
"Rising temperatures may trigger weather extremes and surprises, such as more rapid melting of the Arctic sea ice than projected," Schwartz said. "The highways that currently serve as evacuation routes and endure periodic flooding could be compromised with strong hurricanes and more intense precipitation, making some of these routes impassable."
Transportation providers will need to focus on evacuation planning and work more closely with weather forecasters and emergency planners, the said the committe, which includes meteorologists, climate scientists and planners as well as transportation officials from Massachusetts, New York, Texas and California.
"It is now possible to project climate changes for large subcontinental regions, such as the Eastern United States, a scale better suited for considering regional and local transportation infrastructure," Schwartz said.
The U.S. transportation system was designed and built for local weather and climate conditions, predicated on historical temperature and precipitation data, but the report finds that climate predictions used by transportation planners and engineers may no longer be reliable for forecast weather and climate extremes.
Infrastructure pushed beyond the range for which it was designed can become stressed and fail, as seen with loss of the U.S. 90 Bridge in New Orleans after Hurricane Katrina.
In addition to climate changes, other vulnerabilities will affect coastal-area transportation systems, the committee notes. Population is projected to grow in coastal areas, which will boost demand for transportation infrastructure and increase the number of people and businesses potentially in harm's way.
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