You have every right to your opinion, and you're welcome to ignore me, but I really don't understand where you're coming from on that. I can think of so many issues with having a privatized road system. Just off the top of my head,

How do these companies get the land? Every libertarian I've asked this of has gone on about how the railroads didn't need government help to get their land, which is provably false (sources 1,2,3). So given that the land is taken by the government then given or sold to the railroads, (or in our case roads) the government is still in the position of forcing the trade and choosing which companies get it.

Then we get to the topic of necessary monopoly. If we don't have a monopoly in charge of a large chunk of land, turning right will cost you an extra $10 as opposed to going straight. For that matter going straight more than 5 miles may cost you an extra $10. (I'm hoping this is uncontroversial enough to not require a source). This is the reason that we have utilities (of which private roads are - at least in my state- already one (source 4)), but this means that the government gets to say how much they're allowed to charge (source 5). If they don't place this regulation, people that live at one end of a private road and work at the other will be required to pay extortionist prices, because there can only be so many roads to get from point a to b. If we do keep those requirements then this is no longer a benefit of using private roads.

Then there's the price difference for the consumer. This one requires some pre-amble.
New Jersey has a population of 9.288 million
Michigan has a population of 10.077 million
(both source 6)
Michigan roads are funded primarily through a (shockingly high) gas tax of 19c/gal (7). (It's largely so high because the wild temperature varrations damage the roads.) The average American uses 489 gal/year (8) for a total average tax of $92.91/year.
The average new Jersey resident pays very little in gas tax, but they do pay for tolls. I can't find an average, but last year the state got ~2 billion (9) in tolls divided by the total number of residents from earlier we can roughly estimate they paid 215.33/year. (This fails to take into account visitors, but in the reverse direction it also fails to account for children and those not driving)

This is in a toll system that, unlike a private one, does not need to turn a profit. To your point on road maintenance being better for toll roads - according to Consumer Affairs NJ is raked 27th in the country for it, while Michigan is 20th (10). US news has NJ at 40, and Michigan at 30 (11).

In the end of the day, it seems to me that people will pay more to drive, and the government will still have such a high level of control of the road system that any benefit that could be found in privatization is lost.

Sources: