The correct thing might be to add the road tax early as to not need to change the TCO calculation later, when people already own the vehicles. To keep encourag

The correct thing might be to add the road tax early as to not need to change the TCO calculation later, when people already own the vehicles. To keep encouraging EV purchases, instead offset the road tax by subsidies for new cars. That brings more cars into the pool. The subsidies can be more or less than the road tax, the point is that the subsidies are trivial to remove later, but a tax is harder and more unfair to those who already purchased a car assuming a specific cost of ownership.