This M11 subway line is for New İstanbul (New Atatürk) airport of İstanbul.

The 37·5 km line is being built by a consortium of Kolin and Şenbay under a December 2016 contract of €999·8m.

This tunnel excavated via several methods.

- Tunnel Boring Machine (Earth Pressure Balance TBM)

- Cut and Cover

- NATM (New Austrian Tunnelling Method)

The opening is delayed to August 2021 from original November 2019.

M11 is only one of the two subway lines to the New Atatürk Airport. The huge airport also has a train line to be served with. The second subway line connect to Marmaray subsea tunnel. Its completes in 2022

Halkalı and airport railway tender is not yet announced.