From the Document: "Federal highway and public transportation programs are funded in surface transportation authorization acts. The five-year Fixing America's Surface Transportation (FAST) Act (P.L. 114-94) was enacted on December 4, 2015. The act was extended by the Continuing Appropriations Act, 2021, and other Extensions Act (P.L. 116-159) for an additional year, through September 30, 2021. The FAST Act, as extended, has provided a modest increase in annual spending on surface transportation from the previous level. It funded this, in part, by transferring $86.3 billion from the Treasury general fund to supplement other revenues that are dedicated to the Highway Trust Fund (HTF), from which federal funds are distributed to state governments and public transportation operators. However, the FAST Act did not address the widening gap between the dedicated revenues flowing into the HTF and the costs of the highway and public transportation programs authorized by Congress. More money will be needed after FY2021 if Congress wishes to continue these programs at their current levels, adjusted for inflation. Congress is expected to address the persistent gap between projected HTF revenues and program costs in surface transportation reauthorization."
CRS In Focus, IF10495
Congressional Research Service: https://crsreports.congress.gov/