I'd guess it is more $ than they will raise with increased taxes.....and if we don't change the congress this election, all those dollars will disappear too.
We're screwed again.
The overwhelming majority—approaching the entirety—of the existing federal gasoline and diesel fuel tax goes to pork barrel projects unrelated to highway capacity expansion or highway maintenance and repair, compensation for bureaucrats, unnecessary “construction” projects like repaving the same road every year (with different potholes this time), and regulatory compliance costs.
An additional federal fuel tax likely will find the same home. Expect the Congress to discern that all roads will fall apart, the economy will collapse, and the terrorists will win unless we spend tens of billions of dollars immediately on such minutiae as a new bus museum in Minnesota, a fishing dock on some lake in Montana, a new fence at a remote airport without regular flights, a palatial post office, and whatever other projects that distinguished members of Congress quite coincidentally believe will enhance their fundraising prospects for the next election.