Define "paid for". Most need maintenance before becoming "paid for" and the maintenance need is an on-going thing. The difference between a toll road and a freeway is where most of the money comes from to build/maintain it. Everyone pays for "Freeways" and the brunt of the cost of a toll road is from the users.
Please most of the money goes to graft, union members and kickbacks. The PA turnpike is nothing but a slush fund. Tolls go up insanely yearly etc.
Once you have them you have government jobs and cash tied to them they never go away.