By Ron Thaniel
May 3, 2010

A major report released by the U.S. Department of Transportation (DOT) on April 20 entitled Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions is, in many ways, an indictment of our nation’s transportation policies and practices that have “created an energy-intensive system dependent on carbon-based fuels and automobiles.”

Presented to Congress by Transportation Secretary Ray LaHood, the report is intended to help inform the debate for the pending federal surface transportation authorization by examining greenhouse gas (GHG) emission levels from the transportation sector. It also analyzes a range of strategies to reduce these emissions.

“Reducing the greenhouse gas emissions that contribute to global climate change is one of the great challenges of our time,” said LaHood. “Transportation is one of the major contributors to greenhouse gases, and the transportation sector must be a big part of the solution.”

Transportation GHG emissions account for 29 percent of the total U.S. GHG emissions, and over five percent of global emissions (about eight percent if GHG emissions from transportation lifecycle processes were included), according to the report. And, from 1990 to 2006 alone, transportation GHG emissions increased 27 percent, accounting for almost one-half of the increase in total U.S. GHG emissions for the period.

In 2006, the report states, emissions from on-road vehicles accounted for 79 percent of transportation GHG emissions. Emissions from light-duty vehicles, which include passenger cars and light duty trucks (e.g., sport utility vehicles, pickup trucks, and minivans) accounted for 59 percent of emissions. Emissions from freight trucks account for 19 percent, and emissions form commercial aircraft (domestic and international) for 12 percent. Emissions from all other modes accounted for less than ten percent of total emissions.

While the report focused on a number of good strategies to reduce transportation GHG emissions, including introducing low-carbon fuels, increasing vehicle fuel economy, and improving transportation system efficiency, the balance of this article is focused on reducing travel that involves carbon emissions and transportation planning and investment – high priorities for the Conference of Mayors in the next federal surface transportation authorization. To view the report online, and all the strategies go to the website http://ntl.bts.gov/lib/32000/32700/32779/DOT_Climate_Change_Report_-_April_2010_-_Volume_1_and_2.pdf.

These strategies, according to the report, would reduce on-road vehicle-miles traveled by reducing the need for travel, increasing vehicle occupancies, and shifting travel to more energy-efficient options that generate fewer GHG emissions. The collective impact of these strategies on total U.S. transportation GHG emissions could range from five to 17 percent in 2030, or six to 21 percent in 2050.

Within these strategies is a significant expansion of urban transit services, in conjunction with land use changes and pedestrian and bicycle improvements. This could generate reductions of two to five percent of transportation GHG by 2030. The benefits would grow over time as urban patterns evolve, increasing to three to ten percent in 2050.

These strategies can also increase mobility, lower household transportation costs, strengthen local economies, and provide health benefits by increasing physical activity.

The report states that transportation planning and investment decisions can integrate transportation and land use planning to reduce travel distances, fund low carbon alternatives, and improve the operating efficiency of the multimodal transportation network.

Strategies that support mixed-use development, mixed income communities, and multiple transportation options can enable travelers to lower trip lengths, reduce trip frequencies, and select more carbon efficient means of travel.

These strategies would lower household transportation costs and reduce dependence on foreign oil, while also reducing greenhouse gas emissions.

“The Obama Administration and DOT are committed to tackling the climate change challenge,” said LaHood. “DOT’s livability initiative and sustainable communities partnership with EPA and HUD recognize that multi-modal transportation combined with mixed-use development and smart community planning are key to reducing greenhouse gas emissions.”