Federal gasoline tax due for a tuneup: "Looking at these numbers, you can begin to understand why the Highway Trust Fund, used to pay for most federal highway and transit programs, is not self-sustaining. In fact, in 2008 and 2009, $15 billion was transferred from the general treasury to the Highway Trust Fund to cover expenses. Even if you removed the 2.8 cents per gallon transit portion of the fund, it would not solve the overall problem: Gasoline taxes are too low to maintain and build our road system."