Study: Global Warming May Weaken Transport Infrastructure

Flooded roads and subways, deformed railroad tracks and weakened bridges may be the wave of the future with continuing global warming, a new study says.

Climate change will affect every type of transportation through rising sea levels, increased rainfall and surges from more intense storms, the National Research Council said in a report released Tuesday.

Complicating matters, people continue to move into coastal areas, creating the need for more roads and services in the most vulnerable regions, the report noted.

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"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 chairman of the committee that wrote the report.

The report cites five major areas of growing threat:

— More heat waves, requiring load limits at hot-weather or high-altitude airports and causing thermal expansion of bridge joints and rail track deformities.

— Rising sea levels and storm surges flooding coastal roadways, forcing evacuations, inundating airports and rail lines, flooding tunnels and eroding bridge bases.

— More rainstorms, delaying air and ground traffic, flooding tunnels and railways, and eroding road, bridge and pipeline supports.

— More frequent strong hurricanes, disrupting air and shipping service, blowing debris onto roads and damaging buildings.

— Rising arctic temperatures thawing permafrost, resulting in road, railway and airport runway subsidence and potential pipeline failures.

The nation's transportation system was built for local conditions based on historical weather data, but those data may no longer be reliable in the face of new weather extremes, the report warns.

The committee said proper preparation will be expensive and called on federal, state and local governments to increase consideration of climate change in transportation planning and construction.

The report notes, for example, that drier conditions are likely in the watersheds supplying the St. Lawrence Seaway and the Great Lakes. The resulting lower water levels would reduce vessel shipping capacity, seriously impairing freight movements in the region, such as occurred during the drought of 1988.

Meanwhile, California heat waves are likely to increase wildfires that can destroy transportation infrastructure.

The outlook isn't all bad, however.

The report says marine transportation could benefit from more open seas in the Arctic, creating new and shorter shipping routes and reducing transport time and costs.

The report was prepared by the Transportation Research Board and the Division on Earth and Life Studies of the National Research Council. The groups are part of the National Academy of Sciences, an independent agency chartered by Congress to advise the government on scientific matters.

Sponsors of the study were the Transportation Research Board, the National Cooperative Highway Research Program, the Transportation Department, the Transit Cooperative Research Program, the Environmental Protection Agency and the Army Corps of Engineers.