Which is the thing people don't get about higher registration fees on electric vehicles and why they may be necessary (sort of). Tax on fuel paid at the pump funds roads, but since EVs aren't buying fuel and weigh as much or more they should probably pay something towards road maintenance. Assuming keep the current funding model, which I'm not convinced is the best model.
I'm fairly pro EV and most taxes like fuel tax have always felt a little regressive even if I'm able to pay for it just fine. I don't know what the actual answer is, but it does seem like the short fall could likely be generated by better taxing wealthy corporations and improving public transportation.