Yes, as gasoline is used less and less, the states have less money to resurface roads and make repairs. So, the mileage idea. For instance, if you had an electric vehicle, you would pay no gasoline tax, but you still use the road. You may pay an additional tax yearly for alternative fuels, but you may drive 100,000 miles a year with this vehicle. Toll roads are another way, but slow down traffic, and sometimes people avoid toll roads. I could see reporting your mileage yearly on your income tax or when you renew your license plates, and pay it then by mileage instead of per gallon, especially with hybrids, electrics, bio-diesel, etc taking to the roads.