01095810

Component

Domestic freight transportation is a rapidly-growing and increasingly significant source of greenhouse gas (GHG) emissions in the United States. According to EPA’s Inventory of Greenhouse Gas Emissions and Sinks, emissions from domestic freight sources increased by 58 percent from 1990 to 2005 – over twice the growth rate of U.S. passenger transportation sources (27 percent) and substantially faster than the increase in GHGs from all U.S. sources (16 percent). This paper seeks to explain the rapid increase in U.S. freight GHG emissions, using activity data from National Transportation Statistics and fuel consumption estimates from Highway Statistics. Measured in emissions per ton-mile, domestic freight movement has become increasingly CO2 intensive since 1990, in contrast to passenger sources, which have produced fewer CO2 emissions per passenger mile. This trend reflects the growing utilization of energy intensive freight modes, especially freight trucks. Another significant factor has been the apparent stagnation and possible decline in truck fuel economy, especially since the mid-1990s. The paper examines national estimates of fuel consumption by trucks and discusses uncertainties in this data. It then highlights strategies for potential reduction in freight emissions and identifies areas for further investigation.

01084478

08-2594

English

15p

2008

Transportation Research Board 87th Annual Meeting

DVD

Figures (2) ; References (35) ; Tables (2)

Air pollution; Carbon dioxide; Diesel engine exhaust gases; Engine efficiency; Engine idling; Forecasting; Freight traffic; Fuel consumption; Greenhouse effect; Trucks

Energy; Environment; Freight Transportation; Highways; Motor Carriers; I15: Environment

Transportation Research Board Annual Meeting 2008 Paper #08-2594

BTRIS, TRIS, TRB

Jan 29 2008 5:01PM