Here in B.C. we have a 10 cent per litter road side improvement tax on gasoline .
Yup right in to general revenue , but we need a referendum to fund bridges and transit .
Why tax the lightweights on the roads when it is the heavy traffic that causes the wear and tear? How many tires your plate is attached to sets the price of your 'fuel' at the end of the year. (say $50k/tire so 4 tires is tax tree until your income is over $200k, 12 tires is $6M is tax tree (before any deductions), etc.
Might I suggest a tightly woven hand stitched hemp outer fabric covered in an hemp epoxy that comes in a variety of dull or vibrant colors that last for years, . . . and years. If the 'heavy loads were forced to travel on the high parts of the road the rutting issue would be eliminated. Bumps that are from high spots could be shaved off by a scrapper towed under the trailer of any length is it is at 3mph. The shavings then go into pot-holes. Cheap and the 'technology' and the manpower is already in place.