Some have said a mileage tax would replace the current gas taxes.
More likely, we will end up with both a mileage tax and a gas tax.
Perhaps electric cars should pay a mileage tax, since they pay no gas taxes.
But as electric car use increases in the years ahead, a mileage tax would be used so that electric car owners are paying taxes to pay for roads.
Maybe off topic, but in some places, gas tax revenue has been diverted to other uses. There really needs to be some structure in place, to ensure that specific taxes paid for specific purposes go only to those purposes.
Or they can just print money until the system collapses.