Change the current federal gasoline tax from its current form of 18.4 cents per gal to a percentage of the price paid.

The current federal tax on gasoline is 18.4 cents per gallon. This rate is based solely on volume and has been in effect since 1997. The need for addition funds for the repair and replacement of our roads and bridges has become critical.
I propose that the rate be changed to a set percentage of the price paid, like most state and local taxes fuel taxes are computed.
With gas prices dropping across the country this is the time to act. The current tax is about 6% of the average price per gallon. The rate should be set at this percentage which would result in little to no change in the amount collected. When gas prices rise again the tax will return additional funds. I estimate that a price increase of 75 cents will result in nearly 1 billion in additional revenue per year.