Tolls on the Interstate highways?

Tolls on the Interstate highways?  The long-standing prohibition has been removed by the Obama administration.  The linked article talks mostly about the fact that the gas tax (a fixed rate per gallon) hasn't been raised for over 20 years, and more gas-efficient vehicles use less gas and therefore contribute less gas tax.  That's all true, but leaves out another factor which is even larger in financial terms: the federal highway trust fund has been increasingly used for “green” that have nothing to do with highways, including projects like trains and metropolitan bus systems.  When the highway trust fund was initially established, it was envisioned as a way to maintain and extend the Interstate U.S. highway system, period.  It has since been “raided” for all sorts of stupid (but politically attractive) ideas.

I'd like to see the trust fund restored to its original purpose, and the gas tax switched to a tax based on mileage times weight.  I can see people throwing things at me already, as my notion would kill a few sacred cows.  However, the current tax system has two enormous distortions in it.  The biggest is that trucking is vastly under-taxed – trucks do the majority of wear-and-tear damage to our highways (because of their weight), but they don't pay a proportional share of the highway tax.  Second, the fuel-based tax effectively subsidizes alternative fueled cars, especially all-electric cars.

There's a refinement to my weight formula that's worth considering, too: using the load per square inch, rather than the total weight of the vehicle.  Such a refinement would encourage trucking companies to use vehicles with more tires (and lower air pressures in those tires), which cause much less wear and tear on the roadways.

But of course none of this will actually happen.  The politicians will keep raiding the trust fund, because it gets them votes.  The taxes will continue to be levied in an irrational way, because it costs less votes (and gathers more campaign contributions from special interest lobbyists).  And I'll continue to wonder whether Winston Churchill was actually correct when he said:

“Democracy is the worst form of government, except for all the other forms that have been tried from time to time.”