we have vehicles and we have roads, and we'll get our roads the same way the government "builds" them, hire a company to lay them down. there are a lot of ways to go about doing this without a government, but i think that automakers would be the top investors in private road building. for example, the cost for them to do so would be offset by something like an increase in car prices, which would still probably be lower than the price of cars now without all the mandatory government regs and taxes inflating their prices. they wouldn't have trouble finding landowners to cooperate in placing roads down (if the landowners don't already pay for it themselves) because road frontage jacks up property value-- a form of profit in its own respect
not to mention the roads would be far better maintained (free market + privatized roads = the customers get what they want, vs a government that says "forget you we're gonna fund the construction of trans bathrooms instead") meaning our supercars may never have to worry about potholes
