Curious about how roads, transit, and bike/ped projects are funded in the U.S.? The Eno Center for Transportation has published a report entitled Highway Trust Fund 101, which answers and provides context for common questions about our nation's transportation funding. Questions include what is the HTF?, how do fuel taxes relate to HTF income?, how does the HTF operate?, etc. In short, the HTF was introduced in 1956 as the funding mechanism for the Federal surface transportation grant-in-aid program. Most recently, MAP-21 has authorized the federal government to legally spend money out of the HTF.
For more information about the Highway Trust Fund, read the report at Eno's website.