The shift in vehicle miles traveled, or VMT, highlights the importance of travel behavior and its influence on LDV energy consumption. Before the 2007 peak, travel behavior in the United States tracked closely with economic growth. Since 2007, trends in US LDV travel have not followed the trends in economic indicators such as income and employment as closely, the EIA says.
Technological changes and improvements can also affect VMT. The increasing fuel efficiency of LDVs can influence personal travel by lowering the marginal cost of driving per mile. As vehicle efficiency improves, individuals can drive the same distance with less fuel and therefore at a lower cost, which may result in an increase in VMT. In recent analyses supporting the promulgation of new final fuel economy and greenhouse gas emissions standards for LDVs in model years 2017 through 2025, the National Highway Traffic Safety Administration and the EPA applied a 10 percent rebound in VMT to reflect the lower fueling costs of more efficient vehicles.
Other types of technological and environmental changes also can affect personal travel. Telecommuting, e-commerce, urbanization, and social media can supplant or complement personal vehicle use. Telecommuting, or working from home, can influence personal VMT. From 1997 to 2010, the share of the workforce working at least one day of the week from home increased from 7 percent to 9.5 percent. As that trend grows, so does the likelihood that individuals will reduce their total miles driven. The share of the working population that works exclusively from home also has increased, from 4.8 percent in 1997 to 6.6 percent in 2010. Although telecommuting can have an impact on reducing VMT, work-related travel in 2009 was only 25 percent of total personal travel.
For a chart on the economy of light-duty vehicles, model year 1975 to 2011, click here.