Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
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Rail
GHG emissions from rail primarily originate from the combustion of diesel fuel
by locomotives, but 8 percent are also attributed to electrically powered trains. 40
Freight sources of rail emissions include: line-haul trains, which travel long
distances on intercity routes; and switchyard locomotives, which move around
rail yards to assemble rail cars into trains. Passenger sources of rail emissions
include urban transit, commuter and inter-city rail. As shown in Figure 2.9a,
GHG emissions from freight rail have steadily increased from 1990 to 2006, while
emissions from passenger rail have increased slightly over the same period.
Increasing freight rail activity, shown in Figure 2.9b, has led to increased freight
rail emissions. However, simultaneous increases in fuel efficiency (also shown in
Figure 2.9b) have counteracted this trend to slow the growth of rail GHG.
Results of a Federal Railroad Administration (FRA) study indicate that railroads
now handle 50 percent more ton-miles of freight than in 1990—using 21.5 percent
less fuel per ton-mile. 41
40 The EPA inventory reports 4.9 million metric tons CO2e from electricity for the total
U.S. transportation sector in 2006. The electricity currently used in transportation is
almost entirely for electrically powered trains.
41 U.S. Department of Transportation, Federal Railroad Administration. Comparative
Evaluation of Rail and Truck Fuel Efficiency on Competitive Corridors. November 2009.