Dues to the associations are assessed based on a legal survey of property size and road use.
For instance, a business that puts many heavy trucks on the road would be assessed accordingly.
About two thirds of the private roads carry fewer than 100 vehicles per day.
They provide not only roads but other municipal services, such as garbage collection and security.
Typically these are neighborhoods where the streets were previously public but have been deeded to the street associations by the city, in exchange for the residents providing their own city services.