America's transportation system continues to change along with the population, labor force, and economy. The following table puts these changes in perspective.
|Resident population (thousands)||248,791||308,745|
|Total areaa (thousand sq. mi.)||3,718||3,797|
|Total civilian labor force (thousands)||125,840||153,889|
|Real gross domestic productb (trillions)||$8.0||$13.1|
|Median household incomeb,c||$41,430||$44,545|
|Average household incomeb,c||$44,122||$56,289|
|Average household expendituresb,c||$39,320||$43,298|
|Number of households (thousands)||94,312||118,682|
|Life expectancy at birth (years)||75.4||78.3d|
aTotal area updated every 10 years.
bData are in 2005 chained dollars (see Glossary for definition).
cAdjusted to chained dollars by BTS in October 2011.
dEstimated by the Bureau of the Census as part of the 2008 National Population Projections.
Sources: Population, Area, Households, Median Income—U.S. Department of Commerce, Bureau of the Census. Average Income, Labor Force, Expenditures—U.S. Department of Labor, Bureau of Labor Statistics. GDP—U.S. Department of Commerce, Bureau of Economic Analysis. Life expectancy—U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and U.S. Department of