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

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
Figure 2.6
Sales of New Passenger Cars and Light Duty Trucks
Number of Vehicles Sold (Millions)
12
10
8
6
4
2
Passenger Cars
Light Trucks
0
1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007
Source: U.S. EPA (2007). Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through
2007.
Medium and Heavy Duty Vehicles
Since 1990, GHG emissions from medium and heavy-duty trucks have increased
77 percent, growing at three times the rate of emissions from light-duty vehicles.
This is the product of decreasing fuel efficiency—as measured per ton-mile
carried—and steadily increasing demand for freight trucking. Between 1990 and
2005, CO 2 emissions per ton-mile carried increased almost 13 percent, while
actual ton-miles carried increased 58 percent. 35 These changes were driven by an
expansion of freight trucking after economic deregulation of the trucking
industry in the 1980s; widespread adoption of just-in-time manufacturing and
retailing practices by business shippers and receivers, increasing highway
congestion; and structural changes in the economy that produce higher-value,
lower-weight, and more time-sensitive shipments better served by trucking.
GHG emissions from freight trucks have increased at a greater rate than all other
freight sources, as shown in Figure 2.7.
35 U.S. EPA (2008). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 to 2006.
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