Thanks for the interesting point about transfer numbers, hfly. I have something to report about rail links to the new airport. Judging by their replies to questions on social media, the airport seems adamant that phase 1 of the metro link to the city will be completed for the opening of phase 1 of the airport in October. That is to say, they seem no less sure of this than of the opening date of the airport, so my bet is on the metro line opening at the same time as phase 1 of the airport, whether that be on time or late.

They also said that it was a condition of their BOT agreement that the first of two metro lines to the city be built to open with the first phase of the airport. I suppose to what degree they'll honour the agreement remains to be seen.

The first phase of the metro connection is a line from Gayrettepe to the airport with a few intermediate stops.