Consumer Price Index for all Urban Consumers (CPI-U) is a measure of the average change over time in the prices urban consumers paid for a market basket of consumer goods and services. Consumer Price Indexes (CPI) for particular goods and services, such as ones related to transportation, show changes in prices paid by consumers for transportation related goods and services. Comparing the CPI-U and the CPI for transportation shows which transportation items are contributing to changes in the consumer cost of living, and comparing mode specific CPIs shows which modes of transportation are becoming more expensive relative to other modes of transportation.

SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, 2016.