May 25, 2009

Transportation is a major source of human-caused GHG emissions, contributing 32 percent of U.S. CO2 emissions and 28 percent of all U.S. GHGs in 2006. U.S. transportation emissions account for a large portion of national and global emissions.

Impacts on Infrastructure

Climate change could impact transportation systems in a variety of ways, and differently in each region. Sea-level rise could inundate and damage coastal infrastructure in low-lying areas or make it more vulnerable to storm surges. Increases in storm intensity would have serious impacts on transportation operations and infrastructure. These impacts may require changes in transportation facility location, design, construction, and operations.

There are four primary ways to reduce GHG emissions from transportation.

1 Improve system and operational efficiencies: Traffic flow improvements can be achieved through intelligent transportation systems, route optimization, congestion pricing, and enhanced intermodal links and system connectivity. Operational efficiencies can be achieved through improving vehicle maintenance and reducing idling of freight vehicles.

2 Reduce growth of vehicle miles traveled (VMT): Implementing land-use strategies that help to concentrate development can lessen the need to drive. Pricing mechanisms such as road pricing and mileage-based car insurance can also motivate people to drive less.

3 Transition to lower-GHG fuels: Gasoline and diesel can be replaced with fuel such as biodiesel and natural gas, which can emit fewer GHGs over their lifecycle – from production to final use.

4 Improve vehicle technologies: The development of more fuel-efficient vehicles can be promoted through policy decisions, tax credit programs, and feebates.

For more information, go to the Federal Highway Administration website at http://www.fhwa.dot.gov/hep/climate/ccbrochure.htm.