WASHINGTON (AP) — The incoming chairman of the Senate Commerce, Science and Transportation Committee says raising the federal fuel taxes is among the options under consideration to replenish the dwindling Highway Trust Fund.

Sen. John Thune of South Dakota says all options must be looked at to fill an enormous shortfall when the existing highway legislation expires in May.

Gas and diesel taxes haven't risen since 1993, resulting in perennial shortfalls in the fund that pays for most road projects.

Several commissions have called for raising the taxes, but Congress has been reluctant. Instead lawmakers have dipped repeatedly into the general treasury to keep the trust fund solvent.

The federal gas tax is 18.4 cents per gallon and the diesel tax is 24.4 cents per gallon.

Thune spoke on "Fox News Sunday."