Once everyone is driving a Tesla, and filling up for "free", where do the taxes come from to pay for the infrastructure? In Australia, the high price of fuel c

Once everyone is driving a Tesla, and filling up for "free", where do the taxes come from to pay for the infrastructure? In Australia, the high price of fuel comes because the government puts something like a 50+% tax on it. Most people (incorrectly) assume that your car registration pays for infrastructure dev/maint, but car registration just pays for insurance/payouts for car crashes, and running of the registration system. Most of themoney used to build and maintain roads, highways, etc, comes from the fuel tax. If we transfer to a new form of fuel that is supposedly free as this article suggests, where does the aus government look to get the money to pay for the roads?