I'm starting a new research on the opens spaces in the contemporary city and their sustainability. Public spaces thought as a single element and in a network.
I worked about former periods. During the early modern period, french city councils considered public sustainability as a major stake. They fought against private usurpations and sometimes put special signs affirming the public character of a way.
Small parts of public space were only sold by city council when it permitted the realization of street alignments.
You can look at this book which is out in two weeks time: https://ribabookshops.com/item/urban-lighting-for-people-evidence-based-lighting-design-for-the-built-environment/40315/
and a chapter in the above book I have written based on Kings Cross development in London/UK: