Unadjusted dollar amounts reflect actual year-of-expenditure dollars.

The CPI (Consumer Price Index) is used to adjust year-of-expenditure dollars to 2019 dollars from a consumer's perspective. The U.S. Department of Labor develops the CPI based on monthly data on changes in the prices paid by urban consumers for a representative basket of goods and services.

The PPI (Producer Price Index) is used to adjust year-of-expenditure dollars to 2019 dollars from a producer's perspective. The U.S. Department of Labor develops the PPI to measure the average change over time in the selling prices received by domestic producers for their output. The prices included in the PPI are from the first commercial transaction for many products and some services.

The NHCCI (National Highway Construction Cost Index) is used to adjust year-of-expenditure dollars to 2019 dollars from a highway construction cost perspective. The Federal Highway Administration develops the NHCCI to measure price changes in highway construction costs.