With respect to energy and the environmental aspect of transportation:

• Transportation relies almost entirely on petroleum to move people and goods. Recent trends, however, show decreasing transportation dependence on imported oil primarily due to the introduction of domestically produced ethanol in gasoline and increased domestic oil production.
• The highway mode dominates transportation energy use, accounting for 83.5 percent of the total in 2011. Personal vehicles, such as passenger cars, sport utility vehicles, minivans, and pick-up trucks, accounted for 73.7 percent of highway energy use and 61.5 percent of total transportation energy use.
• Transportation is the second largest producer of greenhouse gas emissions, accounting for 27.3 percent of the U.S. total in 2011. Since 2005 transportation-produced greenhouse gases have been decreasing because of improved energy efficiency, less vehicle travel, and increased use of biofuels.
• All transportation-related air pollutant emissions are lower than they were in 1990, resulting in improved air quality in many urban areas. The number of days that resulted in the nonattainment of at least one national air quality standard in an urban area decreased from 4,091 in 1990 to 1,012 in 2010.

FIGURE 7 Energy Use by Mode of Transportation: 2011

Table Version | Excel

KEY: Btu = British thermal unit

SOURCE: Various sources as cited in U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics, Table 4-6, Available at http://www.bts.gov as of November 2013.