An idea of corporatocracy (pretty dystopian) exists in some movies and videogames. Typically huge corporations ar epresented as having own armies and those armies can force citizens do their work. We could actually even call each corporation a small state.
And I wondered about question in the title. Suppose even such a problem as road building. Indeed, in such a system all roads would be toll roads. How would road building corporations between each other decide who where builds roads? Maybe it can be done by the right of fastest. I see no problem for a corporation to build roads on several adjacent streets. But then suppose roads became bad after some time. Now what would be a reason for a corporation to fix them? What would be a reason for a corporation not to set to high tolls? So, it turns out that already laissez-faire capitalism turns to corporatocracy and is incompatible with ideas of libertarianism.
To strengthen the argument suppose the case when in order to leave your home and drive somewhere you need to use the roads of the same corporation. That is all the roads in the city block belong to the same corporation. Therefore, it defeats the purpose of capitalism itself: competition. And it forces people in given city block to pay unreasonably high tolls.
How is this issue resolved by laissez-faire capitalists?