I am sharing this article from Business World about the idea (or is it already a proposal) for an MMDA Transport Authority. I seem to recall there were already proposals for something like this but I have to check for references and sources. In the meantime, I am content with sharing the following:

On Nov. 11, 1999, the British Parliament established the Greater London Authority. Prior to that, there was no single entity managing the entirety of London. The governance of the city was fragmented, and responsibilities for planning, transport, and other city-wide matters were divided between local boroughs and national authorities. The Greater London Authority was established […]

Source: Needed: MMDA Transport Authority similar to Transport for London