The real solution would be to RAISE the gasoline, Diesel and LNG taxes based on tons of pollutants per mile. Use the money to restore the US highway system to what it was 33 years ago before the US stopped maintaining our transportation system.
I generally hate the politics of "fair" taxes, as they generally are made out to help out a special interest. Still this special interest - lng for truck fuel versus diesel has a big point. Why should diesel be favored in the tax code above lng? Using domestic natural gas does help the US economic security, and on this memorial day, we should remember those that served our country, even in misguided attempts by our leaders to control oil. Ignore the lower pollution of lng versus diesel, simply from a energy security point of view we should change any tax code that favors diesel over natural gas. Energy is one area of the tax code that can be fairly easily reformed. Remove tax breaks for drilling. Remove tax credits for fuel oil. Tax oil per barrel to decrease its use, and pay for roads. Remove the ethanol mandate, except where it actually reduces pollution (not sure if that is anywhere). Set the open fuel standard to have new light vehicles able to use higher ethanol and methanol blends.
Don't think we want to do that. Better to tax by tons per mile of greenhouse gases which gets to the heart of the global warming issue caused by fossil fuels. Other issue is imported oil and tax to reduce that and pay for the costs to date.