The transportation sector consists of private and public vehicles that move people and commodities. Included are automobiles, trucks, buses, motorcycles, railroads, aircraft, ships, barges, and natural gas pipelines. Natural gas use reflects the fuel needed to move natural gas through a pipeline to end users in the residential, commercial, industrial, and electric power sectors. Since 1990, natural gas consumption also includes natural gas consumed as vehicle fuel.
Using an equivalent measure of million British thermal units (Btu), the graph below compares the prices of fuel. The prices are also in nominal dollars to provide a better comparison. In 2015, lubricants had the highest price of $67.28 per million Btu. Propane was $26.21, aviation gasoline was $24.86, motor gasoline was $19.80, diesel fuel was $19.39, natural gas was $18.41, and jet fuel was $11.88. In 2015, if there was any coal, electricity, or residual fuel consumption in the transportation sector, the amounts were small enough to round to zero, and prices were not reported. The price for ethanol was not tracked, and there were no direct fuel costs for hydroelectric, geothermal, wind, photovoltaic, or solar thermal energy, so no prices were reported for these fuels.