Why aren't there more private roads?

[CallMeIshmael]

It seems that nearly 100% of roads in North America are publically owned. Not quite 100%, but a very very high percentage of them.


Beyond that, it doesnt seem that there is any legal barrier to erecting private roads, since they do exist.


Why is this?


Is there some barrier to entry into this market, or is this a (nearish) monopoly?


EDIT: Just to be absolutely certain: 1) Im well aware of te governments acts, and how, since they charge us taxes, that is a barrier to entry, but Im just curious if that isthe only 1 and 2) This isnt meant to be an anti-AC thread in any way. Just a question.