Thank you for asking.
The people who own them could certainly make agreements with their customers to allow use of them couldn't they ?
"could certainly"? Try 'certainly not'.
A road is needed in a 12 mile stretch connecting Getreal to Cmonman and your home in Utopia is right in the middle.
A thousand homes would have access to the road. 900 'contributors' are needed to fund it.
The road builder canvasses the homes, and finds 600 homes enthusiastic about the needed road. But 150 of these say their budget is maxxed out, and can't afford to fund the road. You REALLY want the road, and have plenty of cash, so you say you'll cover those 150 'yes' but poor homes.
100 residents live there specifically because there are no incoming or outbound roads.
The other 300 residents would actually like having this road, but they figure there's plenty more people like you that will pay much more than their own share. So they don't pay, but still expect the road to be built. In days ahead, they begin protesting in front of your home, calling you all sorts of nouns for not subsidizing all of your 'less fortunate' neighbors.
You take a knee with them, promise to help paint 'Less Fortunate Lives Matter' on the new road, but it's not enough. A couple of weeks later, you put your home on the market and flee, cursing the militant less fortunates as your U-Haul trods along the path where the road would have been. When you find pavement, you soon pass Acme Road Builders, and see a "building for lease' sign on the window.