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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
ridership peaked at about 130 million passengers in 1970 and is currently about 40 million
annual passengers. Recent increases in scheduled intercity bus service, resulting from
market demands due to higher fuel prices, led to a 9.8 percent growth in departures in
2008 (DePaul University, 2008). This marks two consecutive years of robust growth after
more than four decades of persistent decline.
Intercity bus and rail passenger services could be expanded by:
• Increasing investment in Amtrak’s system, to create new intercity corridor service and
to increase speeds, service frequencies, and/or reliability on existing routes;
• Investing in high-speed rail systems (whether operated by Amtrak or another carrier)
that have been identified by the Federal Railroad Administration (FRA) in 12 intercity
markets around the country; and
• Providing capital and/or operating subsidies to intercity bus service providers, to
expand service and attract greater ridership.
Magnitude and Timing of Greenhouse Gas Reductions
Figure 5.4 shows average energy consumption for passenger-mile for intercity passenger
rail, intercity buses, automobiles, and aircraft. The data show that intercity passenger rail
(Amtrak) consumes 17 percent less energy per passenger-mile than air travel and
31 percent less energy per passenger-mile than the average private vehicle (automobile or
light truck) (ORNL, 2007). Based on fuel consumption and operating data from
Greyhound, intercity buses are approximately 81 percent more efficient than intercity rail
as estimated by ORNL. This chart gives a general indication of the relative GHG impacts
of these various modes. 23
23 Energy consumption will be roughly but not completely proportional to GHG emissions. GHG
emissions from electrified intercity rail will depend upon the electricity generation mix, and
aviation may have additional global warming impacts from contrail formation. There are also
minor differences in the energy and carbon content of gasoline, diesel, and aviation fuel.
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