Considering what I do for a living (Provincial tax auditor, specializing in fuel tax) I have been trying to get our province on board with some form of taxes that is fair. Due to vehicles having yearly registration in NB, my suggestion is tracking yearly odometer readings when a car renews registration.
Using this data you can determine a proper amount of road tax based on distance and the weight of the vehicle. But this data wouldn’t only be valuable for taxing electric vehicles, this data could be used for many things. Tracking distances travelled in regions, this data can be used to help determine why certain areas have higher distances travelled. This could help highlight places and regions that could benefit either from more access to necessities, new infrastructure, and to track trends.
But like everything government, getting new things developed and adopted is extremely hard and unless you can highlight a large revenue increase it’s not high on the priority list.