> whether they're completely treating federal roads separately or using it for the total, etc
The tax does not distinguish types of road, much like a gas tax does not.
The context we were in is Utah gas taxes and how much it affects road funding that Utah does. Were you referring to something different? I would assume that Utah gas taxes, if they are intended to fund road work, would go towards state roads in Utah (but that's just an assumption, which is why I was interested in the source).
And yes, it’s less efficient than a carbon tax, but fundamentally you cannot deny the net effect of getting rid of the conservation aspect of gas taxes BEFORE passing a compensating carbon tax would have the effect of basically eliminating a carbon tax.
In other words, let’s talk about adding compensatory EV fees AFTER passing a carbon tax. Sounds fair and certainly better for climate.