To my knowledge, in France, the national road systems are private (but weren't always) and charge massive tolls, but maintenance is paid for by contracts from the government. So all of the private owners of the roads also run sister companies that do maintenance. The government pays exorbitant prices to the companies to do maintenance for the roads that they then also make large amounts of toll from.

I'm not saying I fully support private roads or public roads, but the worst combination is a little bit of both...