M Asher, S Sheikh and V Ramakrishnan have a piece on this shift of ownership.
How a large transport sector PPP (Public Private Partnership) in UK, a high-income country, with a reputation for good public financial management, came to be restructured from a PPP to full public sector control in less than a decade, and the implications this episode holds for India, a middle-income country.
Infra is not just an ownership thing as we like to assume. Infact most infra worldwide has been built by public sector only. What matters more is the microeconomics and incentives around the sector. One has to think deeper through the contracts involved, pricing, scale and so on.