Part of the issue is that of the $2 trillion needed, the current administration’s proposal is to provide $200 million in traditional funding with the rest being backed up the private sector in the form of P3’s - aka tolls. Quite frankly, I’d rather see a national gas tax increase. It’s unpopular, including among people I know personally, but it’s desperately needed if we are serious about rebuilding our infrastructure and keeping what’s toll free now that way in the future.
In a general sense that seems logical, but there have been many calls for getting the federal government out of funding highways for the last 40 years or more, especially in the last 20 years or so, and devolving it to the states and localities.
FHWA still provides about $45 billion per year in federal-aid funding to the states. But by keeping the federal highway user tax rates static since 1992, that has caused a steady devolvement of highway funding to the states and localities.
This is from 2015 and quotes summaries from a few years before, but it shows how heavy is the funding levels from the states and localities.
The revenue collected in 2012 from all levels of government for highways and bridges was $216.6 billion, as illustrated in Exhibit 6-1. Of the total revenues generated, the Federal government contributed $42.8 billion; State governments, $106.3 billion; and local governments, $67.5 billion.
https://www.fhwa.dot.gov/policy/2015cpr/chap6.cfm