There's absolutely special buckets of road money.
For example
In NC each dollar collected in gasoline taxes goes directly to one of two different highway funds (the split between them also set by law) and that money can ONLY be used for that purpose.
For the vast majority the EV tax is cheaper.
Someone posted the state by state list of EV charges earlier, in virtually every case it's quite low compared to the gas tax for an average # of miles in an average ICE vehicle.
To give an example again from my state- it's $130 for an EV.
The gasoline tax is 36.1 cents per gallon. The average ICE vehicle in the US fleet gets ~25 mpg, and drives (outside of covid) about 13,500 miles per year.
That's 540 gallons of gas, which is $194.94.
So about 1/3rd
more the average driver pays in fuel taxes than I pay for the EV registration tax.
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EDIT- actually it's even worse for the ICE driver.... there's also the 18.3 cent FEDERAL gas tax, there's no equivalent for EVs there... so at 540 gallons of gas that's
another almost $100 a year in FEDERAL gas tax the EV driver doesn't have to pay.
Meaning the gas car on average is paying almost $300 yr, vs the EV driver paying the $130 tax.
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Obviously there'll be exceptions (esp. for low-miles drivers in a Prius or something since the EV tax is flat and the gas tax is effectively per mile based on MPG) but for most? The EV tax is lower currently.
As more EVs get on the road that's likely to have to change though because the roads still need funding.