Source: BTS, National Transportation Statistics.

Energy Consumption by Transportation Mode in the United States, 1960-2010 (in Trillion BTUs)

Road accounts for about 84% of all the energy consumed by transportation in the United States and this share has remained relatively constant in time. After decades of continuous growth, energy consumption appears to be leveling of. This is in part due to the growing energy efficiency of modes as well as lower economic growth prospects.