I stopped reading at people building their own road lol... that's totally insane.
Seriously do you have an idea of the cost of a road by km ?
I don't mean dirt road... but if it is your idea of road... that's pretty much what you will get from your neighborhood association, or may-be you just meant in front of your garage ?

Now lets connect cities to cities... so who pays ? Not your neighborhood not the city. So who pays for it ? Donations ?
Lets do donation... well some won't pay because they don't want to go to that city, but rather the other one... lol (hey anarchy... everyone have the right to have their own priorities...).
So yeah, actually you found why anarchy can't work, because for any billion dollars/large infrastructure project, you can't get the money because people don't have to agree with your priorities or can't just set priorities...

So how do you "make" people set priorities ?
voting ? well no go (from what I read so far)
Government ? no way
So what would happen in practice, a comity of "elite" where "non-leader". Since they can't be any leader in anarchy... lets call them "comrades" (lol) so it doesn't reflect ranks or whatever) would decide for the good of everyone... and silence those who would be too vocal against one project or another...
and we end up with a dictatorship like at the beginning of the soviet era...