I'm ignoring the weight increase, just saying that people that only own EVs will not pay the gas tax, and will therefore contribute far less to the cost of road maintenance.
There's a similar shifting dynamic in solar power, where much of the cost of utilities is actually for distribution and maintenance, and as long as you're connected to the grid you're contributing to that cost, but to encourage people to use less power more of the cost is priced into the $/kWh price, which all breaks down when you're generating most of your own power but still using the grid.
It's an interesting economic problem, and I don't think there are any super obviously "fair" solutions right away.
Oh, that's true. Oftentimes these are ways of shifting costs from people inside the new market to people in the old market. This actually accelerates adoption of new technology, because not only do you reap the benefits, but you offload the externalities onto people who haven't switched yet, incentivizing them to switch.
I can think of a lot of examples, eg. Internet media destroyed the monopoly of old media, which made it uneconomical to do serious investigative journalism, which further reduced the quality of old-line media, which accelerated the switch to Internet media. Private/magnet/charter schools brain-drain the best students out of public schools, which decreases the quality of instruction, which means that you need to start looking at private/magnet/charter schools if you want your kid to have a decent education. Automobiles incentivized the creation of road networks and parking lots, which took up so much space that you can no longer walk anywhere, which requires that you get a car.
Usually it results in the total destruction of the old industry, and then the new industry develops some taxation/regulation scheme to cover common goods within the new technology regime.
Seeing as only 41% of road costs are paid for by license + fuel taxes, those EV owners are already paying for more than half the cost of the roads through state/federal income taxes.
By the time this is a concern, our elected and institutional government workers will have figured out how to take the tax out of charging stations or car sales or whatever.
There's a similar shifting dynamic in solar power, where much of the cost of utilities is actually for distribution and maintenance, and as long as you're connected to the grid you're contributing to that cost, but to encourage people to use less power more of the cost is priced into the $/kWh price, which all breaks down when you're generating most of your own power but still using the grid.
It's an interesting economic problem, and I don't think there are any super obviously "fair" solutions right away.